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  • 1.
    Ahl, David
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi, Integrativ Fysiologi.
    Liu, Haoyu
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi.
    Schreiber, Olof
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi.
    Roos, S.
    Swedish Univ Agr Sci, Uppsala BioCtr, Dept Microbiol, Uppsala, Sweden..
    Phillipson, Mia
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi, Integrativ Fysiologi.
    Holm, Lena
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi, Integrativ Fysiologi.
    Lactobacillus reuteri increases mucus thickness and ameliorates dextran sulphate sodium-induced colitis in mice2016Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 217, nr 4, s. 300-310Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aim: The aim of this study was to investigate whether two Lactobacillus reuteri strains (rat-derived R2LC and human-derived ATCC PTA 4659 (4659)) could protect mice against colitis, as well as delineate the mechanisms behind this protection.

    Methods: Mice were given L.reuteri R2LC or 4659 by gavage once daily for 14days, and colitis was induced by addition of 3% DSS (dextran sulphate sodium) to drinking water for the last 7days of this period. The severity of disease was assessed through clinical observations, histological evaluation and ELISA measurements of myeloperoxidase (MPO) and pro-inflammatory cytokines from colonic samples. Mucus thickness was measured invivo with micropipettes, and tight junction protein expression was assessed using immunohistochemistry.

    Results: Colitis severity was significantly reduced by L.reuteri R2LC or 4659 when evaluated both clinically and histologically. The inflammation markers MPO, IL-1, IL-6 and mKC (mouse keratinocyte chemoattractant) were increased by DSS and significantly reduced by the L.reuteri strains. The firmly adherent mucus thickness was reduced by DSS, but significantly increased by L.reuteri in both control and DSS-treated mice. Expression of the tight junction proteins occludin and ZO-1 was significantly increased in the bottom of the colonic crypts by L.reuteri R2LC.

    Conclusion: These results demonstrate that each of the two different L. reuteri strains, one human-derived and one-rat-derived, protects against colitis in mice. Mechanisms behind this protection could at least partly be explained by the increased mucus thickness as well as a tightened epithelium in the stem cell area of the crypts.

  • 2.
    Anderberg, S. B.
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    Luther, Tomas
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    Frithiof, Robert
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    Physiological aspects of Toll-like receptor 4 activation in sepsis-induced acute kidney injury2017Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 219, nr 3, s. 575-590Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Sepsis-induced acute kidney injury (SI-AKI) is common and associated with high mortality. Survivors are at increased risk of chronic kidney disease. The precise mechanism underlying SI-AKI is unknown, and no curative treatment exists. Toll-like receptor 4 (TLR4) activates the innate immune system in response to exogenous microbial products. The result is an inflammatory reaction aimed at clearing a potential infection. However, the consequence may also be organ dysfunction as the immune response can cause collateral damage to host tissue. The purpose of this review is to describe the basis for how ligand binding to TLR4 has the potential to cause renal dysfunction and the mechanisms by which this may take place in gram-negative sepsis. In addition, we highlight areas for future research that can further our knowledge of the pathogenesis of SI-AKI in relation to TLR4 activation. TLR4 is expressed in the kidney. Activation of TLR4 causes cytokine and chemokine release as well as renal leucocyte infiltration. It also results in endothelial and tubular dysfunction in addition to altered renal metabolism and circulation. From a physiological standpoint, inhibiting TLR4 in large animal experimental SI-AKI significantly improves renal function. Thus, current evidence indicates that TLR4 has the ability to mediate SI-AKI by a number of mechanisms. The strong experimental evidence supporting a role of TLR4 in the pathogenesis of SI-AKI in combination with the availability of pharmacological tools to target TLR4 warrants future human studies.

    Fulltekst (pdf)
    fulltext
  • 3.
    Apró, William
    et al.
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Eva Blomstrands forskningsgrupp.
    Blomstrand, Eva
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Eva Blomstrands forskningsgrupp.
    Influence of supplementation with branched-chain amino acids in combination with resistance exercise on p70S6 kinase phosphorylation in resting and exercising human skeletal muscle.2010Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 200, nr 3, s. 237-48Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    AIM: Skeletal muscle growth is thought to be regulated by the mammalian target of rapamycin (mTOR) pathway, which can be activated by resistance exercise and branched-chain amino acids (BCAA). The major aim of the present study was to distinguish between the influence of resistance exercise and BCAA on key enzymes considered to be involved in the regulation of protein synthesis, including p70(S6) kinase (p70(S6k)). METHODS: Nine healthy subjects (four men and five women) performed unilateral resistance exercise on two occasions separated by 1 month. Subjects were randomly supplied either a mixture of BCAA or flavoured water. Muscle biopsies were taken from both resting and exercising muscle before, after and 1 h after exercise. RESULTS: Phosphorylation of Akt was unaltered by either resistance exercise and/or BCAA supplementation whereas mTOR phosphorylation was enhanced (P<0.05) to a similar extent in both exercising and resting muscle following exercise in the absence (70-90%) and presence of BCAA supplementation (80-130%). Phosphorylation of p70(S6k) was unaffected by resistance exercise alone; however, BCAA intake increased (P<0.05) this phosphorylation in both legs following exercise. In resting muscle, a 5- and 16-fold increase in p70(S6k) was observed immediately after and 1 h after exercise, respectively, as compared to 11- and 30-fold increases in the exercising muscle. Phosphorylation of eukaryotic elongation factor 2 was attenuated 1 h after exercise (P<0.05) in both resting (10-40%) and exercising muscle (30-50%) under both conditions. CONCLUSION: The present findings indicate that resistance exercise and BCAA exert both separate and combined effects on the p70(S6k) phosphorylation in an Akt-independent manner.

  • 4.
    A'Roch, Roman
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Steendijk, Paul
    Oldner, Anders
    Weitzberg, Eddie
    Konrad, David
    Johansson, Göran
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Left ventricular mechanical dyssynchrony is load independent at rest and during endotoxaemia in a porcine model2009Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 196, nr 4, s. 375-383Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    AIM: In diseased or injured states, the left ventricle displays higher degrees of mechanical dyssynchrony. We aimed at assessing mechanical dyssynchrony ranges in health related to variation in load as well as during acute endotoxin-induced ventricular injury.

    METHODS: In 16 juvenile anaesthetized pigs, a five-segment conductance catheter was placed in the left ventricle as well as a balloon-tipped catheter in the inferior vena cava. Mechanical dyssynchrony during systole, including dyssynchrony time in per cent during systole and internal flow fraction during systole, were measured at rest and during controlled pre-load reduction sequences, as well as during 3 h of endotoxin infusion (0.25 microg kg(-)1 h(-1)).

    RESULTS: Systolic dyssynchrony and internal flow fraction did not change during the course of acute beat-to-beat pre-load alteration. Endotoxin-produced acute pulmonary hypertension by left ventricular dyssynchrony measures was not changed during the early peak of pulmonary hypertension. Endotoxin ventricular injury led to progressive increases in systolic mechanical segmental dyssynchrony (7.9 +/- 1.2-13.0 +/- 1.3%) and ventricular systolic internal flow fraction (7.1 +/- 2.4-16.6 +/- 2.8%), respectively for baseline and then at hour 3. There was no localization of dyssynchrony changes to segment or region in the ventricular long axis during endotoxin infusion.

    CONCLUSION: These results suggest that systolic mechanical dyssynchrony measures may be load independent in health and during acute global ventricular injury by endotoxin. More study is needed to validate ranges in health and disease for parameters of mechanical dyssynchrony.

  • 5. Asgeirsson, D.
    et al.
    Venturoli, D.
    Fries, Erik
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk biokemi och mikrobiologi.
    Rippe, B.
    Rippe, C.
    Glomerular sieving of three neutral polysaccharides, polyethylene oxide and bikunin in rat. Effects of molecular size and conformation2007Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 191, nr 3, s. 237-246Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aim: Polysaccharides and many other non-protein polymers generally have a more open, flexible and asymmetrical structure compared with globular proteins. For a given molecular weight (MW), the Stokes–Einstein radius (ae) of the following polymers increases in the order: Ficoll < dextran ≤ pullulan < polyethylene oxide (PEO). We have tested the hypothesis that such an increase in 'molecular extension' will increase the molecule's glomerular permeability. Thus, we investigated the glomerular sieving coefficients (θ) of the mentioned polymers and of the negatively charged and extended protein bikunin.

    Methods: In anaesthetized Wistar rats, glomerular sieving curves were generated for each FITC-labelled polymer from their respective concentration in urine and plasma, determined by size exclusion chromatography. The θ for bikunin was measured using a tissue uptake technique.

    Results: For a molecule of ae = 55 Å (cf. IgG), θ increased in the order: Ficoll (0.00035 ± 0.000013) < dextran (0.022 ± 0.0029) < pullulan (0.033 ± 0.0024) < PEO (0.12 ± 0.0055). For ae = 36 Å (cf. albumin) the order was: Ficoll (0.076 ± 0.0061) < dextran (0.45 ± 0.037) = pullulan (0.45 ± 0.021) < PEO (0.65 ± 0.0076). θ for bikunin (0.089 ± 0.0045) was 150 times higher than that of albumin, having an equivalent ae and net negative charge.

    Conclusion: From these results it is concluded that for flexible and asymmetric macromolecules, their degree of glomerular hyperpermeability is proportional to their degree of 'molecular extension'. Thus, compared with globular proteins, the polysaccharides investigated, including Ficoll, were found to be hyperpermeable across the glomerular filter in vivo.

  • 6.
    Babateen, Omar M.
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Fysiologi.
    Jin, Zhe
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Fysiologi.
    Bhandage, Amol K.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Fysiologi.
    Korol, Sergiy V.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Fysiologi.
    Westermark, Bengt
    Uppsala universitet, Science for Life Laboratory, SciLifeLab. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för immunologi, genetik och patologi, Neuroonkologi.
    Nilsson, Karin Forsberg
    Uppsala universitet, Science for Life Laboratory, SciLifeLab. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för immunologi, genetik och patologi, Neuroonkologi.
    Uhrbom, Lene
    Uppsala universitet, Science for Life Laboratory, SciLifeLab. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för immunologi, genetik och patologi, Neuroonkologi.
    Smits, Anja
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Neurologi.
    Birnir, Bryndis
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Neurologi.
    GABA-A receptor currents in a cell line (U3047MG) derived from a human glioblastoma tumor are enhanced by etomidate, propofol and diazepam2014Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 211, nr S696, s. 100-100, artikkel-id P74Artikkel i tidsskrift (Annet vitenskapelig)
  • 7. Bak, Z
    et al.
    Sjöberg, F
    Rousseau, A
    Steinvall, I
    Janerot-Sjöberg, Birgitta
    Department of Clinical Physiology, Heart Center, Linköping University Hospital.
    Human cardiovascular dose-response to supplemental oxygen2007Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 191, nr 1, s. 15-24Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    AIM: The aim of the study was to examine the central and peripheral cardiovascular adaptation and its coupling during increasing levels of hyperoxaemia. We hypothesized a dose-related effect of hyperoxaemia on left ventricular performance and the vascular properties of the arterial tree.

    METHODS: Oscillometrically calibrated arterial subclavian pulse trace data were combined with echocardiographic recordings to obtain non-invasive estimates of left ventricular volumes, aortic root pressure and flow data. For complementary vascular parameters and control purposes whole-body impedance cardiography was applied. In nine (seven males) supine, resting healthy volunteers, aged 23-48 years, data was collected after 15 min of air breathing and at increasing transcutaneous oxygen tensions (20, 40 and 60 kPa), accomplished by a two group, random order and blinded hyperoxemic protocol.

    RESULTS: Left ventricular stroke volume [86 +/- 13 to 75 +/- 9 mL (mean +/- SD)] and end-diastolic area (19.3 +/- 4.4 to 16.8 +/- 4.3 cm(2)) declined (P < 0.05), and showed a linear, negative dose-response relationship to increasing arterial oxygen levels in a regression model. Peripheral resistance and characteristic impedance increased in a similar manner. Heart rate, left ventricular fractional area change, end-systolic area, mean arterial pressure, arterial compliance or carbon dioxide levels did not change.

    CONCLUSION: There is a linear dose-response relationship between arterial oxygen and cardiovascular parameters when the systemic oxygen tension increases above normal. A direct effect of supplemental oxygen on the vessels may therefore not be excluded. Proximal aortic and peripheral resistance increases from hyperoxaemia, but a decrease of venous return implies extra cardiac blood-pooling and compensatory relaxation of the capacitance vessels.

  • 8.
    Bak, Zoltan
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Anestesiologi med intensivvård. Linköpings universitet, Hälsouniversitetet.
    Sjöberg, Folke
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Brännskadevård. Linköpings universitet, Hälsouniversitetet.
    Rousseau, Andreas
    Linköpings universitet, Institutionen för medicin och hälsa, Anestesiologi med intensivvård. Linköpings universitet, Hälsouniversitetet.
    Janerot Sjöberg, Birgitta
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    Steinvall, Ingrid
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet.
    Human cardiovascular dose-response to supplemental oxygen2007Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 191, nr 1, s. 15-24Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aim: The aim of the study was to examine the central and peripheral cardiovascular adaptation and its coupling during increasing levels of hyperoxaemia. We hypothesized a dose-related effect of hyperoxaemia on left ventricular performance and the vascular properties of the arterial tree.

    Methods: Oscillometrically calibrated arterial subclavian pulse trace data were combined with echocardiographic recordings to obtain non-invasive estimates of left ventricular volumes, aortic root pressure and flow data. For complementary vascular parameters and control purposes whole-body impedance cardiography was applied. In nine (seven males) supine, resting healthy volunteers, aged 23–48 years, data was collected after 15 min of air breathing and at increasing transcutaneous oxygen tensions (20, 40 and 60 kPa), accomplished by a two group, random order and blinded hyperoxemic protocol.

    Results: Left ventricular stroke volume [86 ± 13 to 75 ± 9 mL (mean ± SD)] and end-diastolic area (19.3 ± 4.4 to 16.8 ± 4.3 cm2) declined (P < 0.05), and showed a linear, negative dose–response relationship to increasing arterial oxygen levels in a regression model. Peripheral resistance and characteristic impedance increased in a similar manner. Heart rate, left ventricular fractional area change, end-systolic area, mean arterial pressure, arterial compliance or carbon dioxide levels did not change.

    Conclusion: There is a linear dose–response relationship between arterial oxygen and cardiovascular parameters when the systemic oxygen tension increases above normal. A direct effect of supplemental oxygen on the vessels may therefore not be excluded. Proximal aortic and peripheral resistance increases from hyperoxaemia, but a decrease of venous return implies extra cardiac blood-pooling and compensatory relaxation of the capacitance vessels.

  • 9.
    Bakalkin, Georgy
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för farmaceutisk biovetenskap.
    The left-right neurohormonal regulation in the brain: Lateralized endogenous opioid system2014Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 211, s. 12-12Artikkel i tidsskrift (Annet vitenskapelig)
  • 10.
    Bakkman, Linda
    et al.
    Mittuniversitetet, Fakulteten för humanvetenskap, Institutionen för hälsovetenskap.
    Sahlin, K
    Holmberg, Hans-Christer
    Mittuniversitetet, Fakulteten för humanvetenskap, Institutionen för hälsovetenskap.
    Quantitative and qualitative adaptation of human skeletal muscle mitochondria to hypoxic compared to2007Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 190, nr 3, s. 243-251Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    AIM: To investigate if training during hypoxia (H) improves the adaptation of muscle oxidative function compared with normoxic (N) training performed at the same relative intensity. METHOD: Eight untrained volunteers performed one-legged cycle training during 4 weeks in a low-pressure chamber. One leg was trained under N conditions and the other leg under hypobaric hypoxia (526 mmHg) at the same relative intensity as during N (65% of maximal power output, W(max)). Muscle biopsies were taken from vastus lateralis before and after the training period. Muscle samples were analysed for the activities of oxidative enzymes [citrate synthase (CS) and cytochrome c oxidase (COX)] and mitochondrial respiratory function. RESULTS: W(max) increased with more than 30% over the training period during both N and H. CS activity increased significantly after training during N conditions (+20.8%, P < 0.05) but remained unchanged after H training (+4.5%, ns) with a significant difference between conditions (P < 0.05 H vs. N). COX activity was not significantly changed by training and was not different between exercise conditions [+14.6 (N) vs. -2.3% (H), ns]. Maximal ADP stimulated respiration (state 3) expressed per weight of muscle tended to increase after N (+31.2%, P < 0.08) but not after H training (+3.2%, ns). No changes were found in state four respiration, respiratory control index, P/O ratio, mitochondrial Ca(2+) resistance and apparent Km for oxygen. CONCLUSION: The training-induced increase in muscle oxidative function observed during N was abolished during H. Altitude training may thus be disadvantageous for adaptation of muscle oxidative function.

  • 11. Bakkman, Linda
    et al.
    Sahlin, Kent
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Forskningsgruppen Mitokondriell funktion och metabolisk kontroll.
    Holmberg, H-C
    Tonkonogi, Michail
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Quantitative and qualitative adaptation of human skeletal muscle mitochondria to hypoxic compared with normoxic training at the same relative work rate.2007Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 190, nr 3, s. 243-51Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    AIM: To investigate if training during hypoxia (H) improves the adaptation of muscle oxidative function compared with normoxic (N) training performed at the same relative intensity. METHOD: Eight untrained volunteers performed one-legged cycle training during 4 weeks in a low-pressure chamber. One leg was trained under N conditions and the other leg under hypobaric hypoxia (526 mmHg) at the same relative intensity as during N (65% of maximal power output, W(max)). Muscle biopsies were taken from vastus lateralis before and after the training period. Muscle samples were analysed for the activities of oxidative enzymes [citrate synthase (CS) and cytochrome c oxidase (COX)] and mitochondrial respiratory function. RESULTS: W(max) increased with more than 30% over the training period during both N and H. CS activity increased significantly after training during N conditions (+20.8%, P < 0.05) but remained unchanged after H training (+4.5%, ns) with a significant difference between conditions (P < 0.05 H vs. N). COX activity was not significantly changed by training and was not different between exercise conditions [+14.6 (N) vs. -2.3% (H), ns]. Maximal ADP stimulated respiration (state 3) expressed per weight of muscle tended to increase after N (+31.2%, P < 0.08) but not after H training (+3.2%, ns). No changes were found in state four respiration, respiratory control index, P/O ratio, mitochondrial Ca(2+) resistance and apparent Km for oxygen. CONCLUSION: The training-induced increase in muscle oxidative function observed during N was abolished during H. Altitude training may thus be disadvantageous for adaptation of muscle oxidative function.

  • 12.
    Barg, Sebastian
    et al.
    Department of Cell Biology, Division of Medicine, Imperial College, London, UK.
    Machado, Jose David
    Compensatory endocytosis in chromaffin cells2008Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 192, nr 2, s. 195-201Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Exocytosis occurs via fusion of secretory granules with the cell membrane, whereupon the granule content is at least partially released and the granule membrane is temporarily added to the plasma membrane. Exocytosis is balanced by compensatory endocytosis to achieve net equilibrium of the cell surface area and to recycle and redistribute components of the exocytosis machinery. The underlying molecular mechanisms remain a matter of debate. In this review, we summarize and discuss recent progress in the understanding of compensatory endocytosis, with the focus on chromaffin cells as a useful model for studying mechanisms of regulated secretion.

  • 13. Barragan, A.
    et al.
    Weidner, J. M.
    Jin, Zhe
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Fysiologi.
    Korpi, E. R.
    Birnir, Bryndis
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Fysiologi.
    GABAergic signalling in the immune system2015Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 213, nr 4, s. 819-827Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    The GABAergic system is the main inhibitory neurotransmitter system in the central nervous system (CNS) of vertebrates. Signalling of the transmitter c-aminobutyric acid (GABA) via GABA type A receptor channels or G-protein-coupled type B receptors is implicated in multiple CNS functions. Recent findings have implicated the GABAergic system in immune cell functions, inflammatory conditions and diseases in peripheral tissues. Interestingly, the specific effects may vary between immune cell types, with stage of activation and be altered by infectious agents. GABA/GABA-A receptor-mediated immunomodulatory functions have been unveiled in immune cells, being present in T lymphocytes and regulating the migration of Toxoplasma-infected dendritic cells. The GABAergic system may also play a role in the regulation of brain resident immune cells, the microglial cells. Activation of microglia appears to regulate the function of GABAergic neurotransmission in neighbouring neurones through changes induced by secretion of brain-derived neurotrophic factor. The neurotransmitter-driven immunomodulation is a new but rapidly growing field of science. Herein, we review the present knowledge of the GABA signalling in immune cells of the periphery and the CNS and raise questions for future research.

  • 14.
    Barragan, Antonio
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut. Karolinska Institutet, Sweden.
    Weidner, Jessica M.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut. Karolinska Institutet, Sweden.
    Jin, Z.
    Korpi, E. R.
    Birnir, B.
    GABAergic signalling in the immune system2015Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 213, nr 4, s. 819-827Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    The GABAergic system is the main inhibitory neurotransmitter system in the central nervous system (CNS) of vertebrates. Signalling of the transmitter c-aminobutyric acid (GABA) via GABA type A receptor channels or G-protein-coupled type B receptors is implicated in multiple CNS functions. Recent findings have implicated the GABAergic system in immune cell functions, inflammatory conditions and diseases in peripheral tissues. Interestingly, the specific effects may vary between immune cell types, with stage of activation and be altered by infectious agents. GABA/GABA-A receptor-mediated immunomodulatory functions have been unveiled in immune cells, being present in T lymphocytes and regulating the migration of Toxoplasma-infected dendritic cells. The GABAergic system may also play a role in the regulation of brain resident immune cells, the microglial cells. Activation of microglia appears to regulate the function of GABAergic neurotransmission in neighbouring neurones through changes induced by secretion of brain-derived neurotrophic factor. The neurotransmitter-driven immunomodulation is a new but rapidly growing field of science. Herein, we review the present knowledge of the GABA signalling in immune cells of the periphery and the CNS and raise questions for future research.

  • 15.
    Bengtsson, Magnus W.
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap.
    Jedstedt, Gunilla
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap.
    Flemström, Gunnar
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap.
    Duodenal bicarbonate secretion in rats: Stimulation by intra-arterial and luminal guanylin and uroguanylin2007Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 191, nr 4, s. 309-317Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aim: Uroguanylin and guanylin are endogenous ligands for guanylate cyclase C, an upstream regulator of the cystic fibrosis transmembrane resistance (CFTR) anion channel, and both peptides increase intestinal anion export in vitro. We have compared the effects of close intra-arterial and luminal administration of uroguanylin and guanylin on duodenal bicarbonate secretion in vivo and studied the interactions with melatonin and cholinergic stimulation.

    Methods: Lewis × Dark Agouti rats were anaesthetized and a segment of the proximal duodenum with intact blood supply was cannulated in situ. Mucosal bicarbonate secretion (pH stat) was continuously recorded and peptides were infused intra-arterially or added to the luminal perfusate.

    Results: Intra-arterial (50–1000 pmol kg−1 h−1) as well as luminal administration (50–500 nmol L−1) of guanylin or uroguanylin caused dose-dependent increases in the duodenal secretion. Luminal administration induced more rapidly appearing rises in secretion and the two peptides induced secretory responses of similar shape and magnitude. The melatonin MT2-selective antagonist luzindole (600 nmol kg−1) significantly depressed the response to intra-arterial guanylins but did not affect secretion induced by luminal guanylins. Similarly, the muscarinic antagonist atropine (0.75 μmol kg−1 followed by 0.15 μmol kg−1 h−1) abolished the response to intra-arterial uroguanylin but caused only slight suppression of the response to luminal uroguanylin.

    Conclusions: Intra-arterial as well as luminal uroguanylin and guanylin are potent stimuli of duodenal mucosal bicarbonate secretion in vivo. The response to luminal guanylins reflects an action at apical receptors. Stimulation by parenteral guanylins, in contrast, is under cholinergic influence and interacts with melatonin produced by mucosal enteroendocrine cells.

  • 16. Bhandage, A. K.
    et al.
    Hellgren, C.
    Jin, Z.
    Olafsson, Einar B.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut.
    Sundström-Poromaa, I.
    Birnir, B.
    Expression of GABA receptors subunits in peripheral blood mononuclear cells is gender dependent, altered in pregnancy and modified by mental health2015Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 213, nr 3, s. 575-585Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    AimThe concept of nerve-driven immunity recognizes a link between the nervous and the immune system. -aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the brain, and receptors activated by GABA can be expressed by immune cells. Here, we examined whether the expression of GABA receptors and chloride transporters in human peripheral blood mononuclear cells (PBMCs) was influenced by gender, pregnancy or mental health. MethodsWe used RT-qPCR to determine the mRNA expression level in PBMCs from men (n=16), non-pregnant women (n=19), healthy pregnant women (n=27) and depressed pregnant women (n=15). ResultsThe 2 subunit had the most prominent expression level of the GABA-A receptor subunits in all samples. The and 2 subunits were up-regulated by pregnancy, whereas the epsilon subunit was more frequently expressed in healthy pregnant women than non-pregnant women who, in turn, commonly expressed the 6 and the 2 subunits. The 1 and epsilon subunits expression was altered by depression in pregnant women. The GABA-B1 receptor was up-regulated by depression in pregnant women, while the transporters NKCC1 and KCC4 were down-regulated by pregnancy. The changes recorded in the mRNA expression levels imply participation of GABA receptors in establishing and maintaining tolerance in pregnancy. Importantly, the correlation of mental health with the expression of specific receptor subunits reveals a connection between the immune cells and the brain. Biomarkers for mental health may be identified in PBMCs. ConclusionThe results demonstrate the impact gender, pregnancy and mental health have on the expression of GABA receptors and chloride transporters expressed in human PBMCs.

  • 17.
    Bhandage, Amol
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Fysiologi.
    Hellgren, Charlotte
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kvinnors och barns hälsa, Obstetrik & gynekologi.
    Jin, Zhe
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Fysiologi.
    Ólafsson, Einar
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Fysiologi.
    Sundström Poromaa, Inger
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kvinnors och barns hälsa, Obstetrik & gynekologi.
    Birnir, Bryndis
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Fysiologi.
    The mRNA expression of GABA-A, GABA-B receptor subunits and chloride transporters in peripheral blood mononuclear cells is influenced by gender, pregnancy and depression2015Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 215, s. 91-91Artikkel i tidsskrift (Annet vitenskapelig)
  • 18.
    Bhandage, Amol K.
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Fysiologi.
    Hellgren, Charlotte
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kvinnors och barns hälsa, Obstetrik & gynekologi.
    Jin, Zhe
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Fysiologi.
    Olafsson, Einar B
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap.
    Sundström-Poromaa, Inger
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kvinnors och barns hälsa, Obstetrik & gynekologi.
    Birnir, Bryndis
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Fysiologi.
    Expression of GABA receptors subunits in peripheral blood mononuclear cells is gender dependent, altered in pregnancy and modified by mental health2015Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 213, nr 3, s. 575-585Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    AIM: The concept of nerve-driven immunity recognizes a link between the nervous and the immune system. γ-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the brain and receptors activated by GABA can be expressed by immune cells. Here we examined if the expression of GABA receptors and chloride transporters in human peripheral mononuclear cells (PBMCs) were influenced by gender, pregnancy or mental health.

    METHODS: We used RT-qPCR to determine the mRNA expression level in men (n=16), non-pregnant women (n=19), healthy pregnant women (n=27) and depressed pregnant women (n=15).

    RESULTS: The ρ2 subunit had the most prominent expression level of the GABA-A receptor subunits in all samples. The δ and ρ2 subunits were up-regulated by pregnancy whereas the ε subunit was more frequently expressed in healthy pregnant women than non-pregnant women who, in-turn, commonly expressed the α6 and the γ2 subunits. The β1 and ε subunits expression was altered by depression in pregnant women. The GABA-B1 receptor was up-regulated by depression in pregnant women while the transporters NKCC1 and KCC4 were down-regulated by pregnancy. The changes recorded in the mRNA expression levels imply participation of GABA receptors in establishing and maintaining tolerance in pregnancy. Importantly, the correlation of mental health with the expression of specific receptor subunits reveals a connection between the immune cells and the brain. Biomarkers for mental health may be identified in PBMCs.

    CONCLUSION: The results demonstrate the impact gender, pregnancy and mental health have on expression of GABA receptors plus chloride transporters expressed in human PBMCs.

  • 19.
    Bhandage, Amol K.
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Fysiologi.
    Hellgren, Charlotte
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kvinnors och barns hälsa, Obstetrik & gynekologi.
    Jin, Zhe
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Fysiologi.
    Olafsson, Einar
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap.
    Sundström, Iinger Poromaa
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kvinnors och barns hälsa, Obstetrik & gynekologi.
    Birnir, Bryndis
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Fysiologi.
    GABA-A receptor subunit expression in human peripheral blood mononuclear cells2014Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 211, nr S696, s. 86-86, artikkel-id P45Artikkel i tidsskrift (Annet vitenskapelig)
  • 20.
    Birnir, Bryndis
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Fysiologi.
    Eliasson, L.
    Lund Univ, Dept Clin Sci Malmo, Ctr Diabet, Lund, Sweden..
    She is in science to stay!2018Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 223, nr 1, artikkel-id e13048Artikkel i tidsskrift (Annet vitenskapelig)
  • 21.
    Bjarnegård, Niclas
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Hjärt- och Medicincentrum, Fysiologiska kliniken US. Reg Jonkoping Cty, Sweden.
    Länne, Toste
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Hjärt- och Medicincentrum, Thorax-kärlkliniken i Östergötland.
    Cinthio, M.
    Lund Univ, Sweden.
    Ekstrand, Jan
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för samhällsmedicin. Linköpings universitet, Medicinska fakulteten.
    Hedman, Kristofer
    Linköpings universitet, Medicinska fakulteten. Region Östergötland, Hjärt- och Medicincentrum, Fysiologiska kliniken US. Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin.
    Nylander, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Hjärt- och Medicincentrum, Fysiologiska kliniken US.
    Henriksson, J.
    Karolinska Inst, Sweden.
    Vascular characteristics in young women: Effect of extensive endurance training or a sedentary lifestyle2018Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 223, nr 2, artikkel-id UNSP e13041Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    AimTo explore whether high-level endurance training in early age has an influence on the arterial wall properties in young women. MethodsForty-seven athletes (ATH) and 52 controls (CTR), all 17-25 years of age, were further divided into runners (RUN), whole-body endurance athletes (WBA), sedentary controls (SC) and normally active controls (AC). Two-dimensional ultrasound scanning of the carotid arteries was conducted to determine local common carotid artery (CCA) geometry and wall distensibility. Pulse waves were recorded with a tonometer to determine regional pulse wave velocity (PWV) and pulse pressure waveform. ResultsCarotid-radial PWV was lower in WBA than in RUN (P amp;lt; .05), indicating higher arterial distensibility along the arm. Mean arterial pressure was lower in ATH than in CTR and in RUN than in WBA (P amp;lt; .05). Synthesized aortic augmentation index (AI@75) was lower among ATH than among CTR (-12.8 1.6 vs -2.6 +/- 1.2%, P amp;lt; .001) and in WBA than in RUN (-16.4 +/- 2.5 vs -10.7 +/- 2.0%, P amp;lt; .05), suggesting a diminished return of reflection waves to the aorta during systole. Carotid-femoral PWV and intima-media thickness (IMT), lumen diameter and radial distensibility of the CCA were similar in ATH and CTR. ConclusionElastic artery distensibility and carotid artery IMT are not different in young women with extensive endurance training over several years and in those with sedentary lifestyle. On the other hand, our data suggest that long-term endurance training is associated with potentially favourable peripheral artery adaptation, especially in sports where upper body work is added. This adaptation, if persisting later in life, could contribute to lower cardiovascular risk.

    Fulltekst (pdf)
    fulltext
  • 22. Blanchard, P. G.
    et al.
    Turcotte, V.
    Cote, M.
    Gelinas, Y.
    Nilsson, S.
    Olivecrona, Gunilla
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk biovetenskap, Fysiologisk kemi.
    Deshaies, Y.
    Festuccia, W. T.
    Peroxisome proliferator-activated receptor activation favours selective subcutaneous lipid deposition by coordinately regulating lipoprotein lipase modulators, fatty acid transporters and lipogenic enzymes2016Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 217, nr 3, s. 227-239Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aim: Peroxisome proliferator-activated receptor (PPAR) γ activation is associated with preferential lipoprotein lipase (LPL)-mediated fatty acid storage in peripheral subcutaneous fat depots. How PPARγ agonism acts upon the multi-level modulation of depot-specific lipid storage remains incompletely understood.

    Methods: We evaluated herein triglyceride-derived lipid incorporation into adipose tissue depots, LPL mass and activity, mRNA levels and content of proteins involved in the modulation of LPL activity and fatty acid transport, and the expression/activity of enzymes defining adipose tissue lipogenic potential in rats treated with the PPARγ ligand rosiglitazone (30 mg kg−1 day−1, 23 days) after either a 10-h fasting period or a 17-h fast followed by 6 h of ad libitum refeeding.

    Results: Rosiglitazone stimulated lipid accretion in subcutaneous fat (SF) ~twofold and significantly reduced that of visceral fat (VF) to nearly half. PPARγ activation selectively increased LPL mass, activity and the expression of its chaperone LMF1 in SF. In VF, rosiglitazone had no effect on LPL activity and downregulated the mRNA levels of the transendothelial transporter GPIHBP1. Overexpression of lipid uptake and fatty acid transport proteins (FAT/CD36, FATP1 and FABP4) and stimulation of lipogenic enzyme activities (GPAT, AGPAT and DGAT) upon rosiglitazone treatment were of higher magnitude in SF.

    Conclusions: Together these findings demonstrate that the depot-specific transcriptional control of LPL induced by PPARγ activation extends to its key interacting proteins and post-translational modulators to favour subcutaneous lipid storage.

  • 23.
    Bohannon, Briana M.
    et al.
    Univ Miami, FL 33136 USA.
    Perez, Marta E.
    Univ Miami, FL 33136 USA.
    Liin, Sara
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelning för neurobiologi. Linköpings universitet, Medicinska fakulteten.
    Larsson, Hans Peter
    Univ Miami, FL 33136 USA.
    omega-6 and omega-9 polyunsaturated fatty acids with double bonds near the carboxyl head have the highest affinity and largest effects on the cardiac I-Ks potassium channel2019Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 225, nr 2, artikkel-id UNSP e13186Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aim The I-Ks channel is important for termination of the cardiac action potential. Hundreds of loss-of-function mutations in the I-Ks channel reduce the K+ current and, thereby, delay the repolarization of the action potential, causing Long QT Syndrome. Long QT predisposes individuals to Torsades de Pointes which can lead to ventricular fibrillation and sudden death. Polyunsaturated fatty acids (PUFAs) are potential therapeutics for Long QT Syndrome, as they affect I-Ks channels. However, it is unclear which properties of PUFAs are essential for their effects on I-Ks channels. Methods To understand how PUFAs influence I-Ks channel activity, we measured effects on I-Ks current by two-electrode voltage clamp while changing different properties of the hydrocarbon tail. Results There was no, or weak, correlation between the tail length or number of double bonds in the tail and the effects on or apparent binding affinity for I-Ks channels. However, we found a strong correlation between the positions of the double bonds relative to the head group and effects on I-Ks channels. Conclusion Polyunsaturated fatty acids with double bonds closer to the head group had higher apparent affinity for I-Ks channels and increased I-Ks current more; shifting the bonds further away from the head group reduced apparent binding affinity for and effects on the I-Ks current. Interestingly, we found that omega-6 and omega-9 PUFAs, with the first double bond closer to the head group, left-shifted the voltage dependence of activation the most. These results allow for informed design of new therapeutics targeting I-Ks channels in Long QT Syndrome.

    Fulltekst (pdf)
    fulltext
  • 24.
    Boushel, Robert
    et al.
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Åstrandlaboratoriet.
    Ara, I
    Gnaiger, E
    Helge, J W
    González-Alonso, J
    Munck-Andersen, T
    Sondergaard, H
    Damsgaard, R
    van Hall, G
    Saltin, B
    Calbet, J A L
    Low-intensity training increases peak arm VO2 by enhancing both convective and diffusive O2 delivery.2014Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 211, nr 1, s. 122-134Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    AIM: It is an ongoing discussion the extent to which oxygen delivery and oxygen extraction contribute to an increased muscle oxygen uptake during dynamic exercise. It has been proposed that local muscle factors including the capillary bed and mitochondrial oxidative capacity play a large role in prolonged low-intensity training of a small muscle group when the cardiac output capacity is not directly limiting. The purpose of this study was to investigate the relative roles of circulatory and muscle metabolic mechanisms by which prolonged low-intensity exercise training alters regional muscle VO2 .

    METHODS: In nine healthy volunteers (seven males, two females), haemodynamic and metabolic responses to incremental arm cycling were measured by the Fick method and biopsy of the deltoid and triceps muscles before and after 42 days of skiing for 6 h day(-1) at 60% max heart rate.

    RESULTS: Peak pulmonary VO2 during arm crank was unchanged after training (2.38 ± 0.19 vs. 2.18 ± 0.2 L min(-1) pre-training) yet arm VO2 (1.04 ± 0.08 vs. 0.83 ± 0.1 L min(1) , P < 0.05) and power output (137 ± 9 vs. 114 ± 10 Watts) were increased along with a higher arm blood flow (7.9 ± 0.5 vs. 6.8 ± 0.6 L min(-1) , P < 0.05) and expanded muscle capillary volume (76 ± 7 vs. 62 ± 4 mL, P < 0.05). Muscle O2 diffusion capacity (16.2 ± 1 vs. 12.5 ± 0.9 mL min(-1)  mHg(-1) , P < 0.05) and O2 extraction (68 ± 1 vs. 62 ± 1%, P < 0.05) were enhanced at a similar mean capillary transit time (569 ± 43 vs. 564 ± 31 ms) and P50 (35.8 ± 0.7 vs. 35 ± 0.8), whereas mitochondrial O2 flux capacity was unchanged (147 ± 6 mL kg min(-1) vs. 146 ± 8 mL kg min(-1) ).

    CONCLUSION: The mechanisms underlying the increase in peak arm VO2 with prolonged low-intensity training in previously untrained subjects are an increased convective O2 delivery specifically to the muscles of the arm combined with a larger capillary-muscle surface area that enhance diffusional O2 conductance, with no apparent role of mitochondrial respiratory capacity.

  • 25.
    Broche, Ludovic
    et al.
    Grenoble, France..
    Gaetano, Perchiazzi
    Univ Bari, Bari, Italy..
    Liisa, Porra
    Univ Helsinki, Helsinki, Finland..
    Angela, Tannoia
    Univ Bari, Bari, Italy..
    Mariangela, Pellegrini
    Univ Bari, Bari, Italy..
    Savino, Derosa
    Univ Bari, Bari, Italy..
    Alessandra, Sindaco
    Univ Bari, Bari, Italy..
    Borges, João Batista
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Klinisk fysiologi.
    Loic, Degrugilliers
    Univ Picardie Jules Verne, Amiens, France..
    Larsson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Hedenstierna, Göran
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Klinisk fysiologi.
    Anthony, Wexler
    Univ Calif Davis, Davis, CA 95616 USA..
    Alberto, Bravin
    ESRF, Grenoble, France..
    Sylvia, Verbanck
    Univ Hosp UZ Brussel, Brussels, Belgium..
    Bradford, J. Smith
    Univ Vermont, Burlington, VT USA..
    Jason, H. T. Bates
    Univ Vermont, Burlington, VT USA..
    Sam, Bayat
    Univ Picardie Jules Verne, Amiens, France..
    Dynamic mechanical interactions between neighboring airspaces determine cyclic opening and closure in injured lung2016Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 217, s. 141-141Artikkel i tidsskrift (Annet vitenskapelig)
  • 26. Calbet, J A L
    et al.
    Boushel, Robert
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Åstrandlaboratoriet.
    Robach, P
    Hellsten, Y
    Saltin, B
    Lundby, C
    Chronic hypoxia increases arterial blood pressure and reduces adenosine and ATP induced vasodilatation in skeletal muscle in healthy humans.2014Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 211, nr 4, s. 574-84Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    AIMS: To determine the role played by adenosine, ATP and chemoreflex activation on the regulation of vascular conductance in chronic hypoxia.

    METHODS: The vascular conductance response to low and high doses of adenosine and ATP was assessed in ten healthy men. Vasodilators were infused into the femoral artery at sea level and then after 8-12 days of residence at 4559 m above sea level. At sea level, the infusions were carried out while the subjects breathed room air, acute hypoxia (FI O2 = 0.11) and hyperoxia (FI O2 = 1); and at altitude (FI O2 = 0.21 and 1). Skeletal muscle P2Y2 receptor protein expression was determined in muscle biopsies after 4 weeks at 3454 m by Western blot.

    RESULTS: At altitude, mean arterial blood pressure was 13% higher (91 ± 2 vs. 102 ± 3 mmHg, P < 0.05) than at sea level and was unaltered by hyperoxic breathing. Baseline leg vascular conductance was 25% lower at altitude than at sea level (P < 0.05). At altitude, the high doses of adenosine and ATP reduced mean arterial blood pressure by 9-12%, independently of FI O2 . The change in vascular conductance in response to ATP was lower at altitude than at sea level by 24 and 38%, during the low and high ATP doses respectively (P < 0.05), and by 22% during the infusion with high adenosine doses. Hyperoxic breathing did not modify the response to vasodilators at sea level or at altitude. P2Y2 receptor expression remained unchanged with altitude residence.

    CONCLUSIONS: Short-term residence at altitude increases arterial blood pressure and reduces the vasodilatory responses to adenosine and ATP.

  • 27.
    Cardinale, Daniele A.
    et al.
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Åstrandlaboratoriet.
    Larsen, Filip J
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Åstrandlaboratoriet, Forskningsgruppen Mitokondriell funktion och metabolisk kontroll.
    Jensen-Urstad, M
    Karolinska institutet.
    Rullman, E
    Karolinska institutet.
    Søndergaard, H
    Rigshospitalet, Köpenhamn, Danmark.
    Morales-Alamo, D
    University of Las Palmas de Gran Canaria, Spanien.
    Ekblom, Björn
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Åstrandlaboratoriet, Björn Ekbloms forskningsgrupp.
    Calbet, J A L
    University of Las Palmas de Gran Canaria, Spanien.
    Boushel, Robert
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Åstrandlaboratoriet. University of British Columbia, Vancouver, British Columbia, Canada.
    Muscle mass and inspired oxygen influence oxygen extraction at maximal exercise: role of mitochondrial oxygen affinity.2019Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 225, nr 1, artikkel-id e13110Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    AIM:We examined the Fick components together with mitochondrial O2 affinity (p50mito ) in defining O2 extraction and O2 uptake during exercise with large and small muscle mass during normoxia (NORM) and hyperoxia (HYPER).

    METHODS:Seven individuals performed two incremental exercise tests to exhaustion on a bicycle ergometer (BIKE) and two on a one-legged knee extension ergometer (KE) in NORM or HYPER. Leg blood flow and VO2 were determined by thermodilution and the Fick method. Maximal ADP-stimulated mitochondrial respiration (OXPHOS) and p50mito were measured ex vivo in isolated mitochondria. Mitochondrial excess capacity in the leg was determined from OXPHOS in permeabilized fibers and muscle mass measured with magnetic resonance imaging in relation to peak leg O2 delivery.

    RESULTS:The ex vivo p50mito increased from 0.06±0.02 to 0.17±0.04 kPa with varying substrate supply and O2 flux rates from 9.84±2.91 to 16.34±4.07 pmol O2 ·s-1 ·μg-1 respectively. O2 extraction decreased from 83% in BIKE to 67% in KE as a function of a higher O2 delivery, and lower mitochondrial excess capacity. There was a significant relationship between O2 extraction and mitochondrial excess capacity and p50mito that was unrelated to blood flow and mean transit time.

    CONCLUSION:O2 extraction varies with mitochondrial respiration rate, p50mito and O2 delivery. Mitochondrial excess capacity maintains a low p50mito which enhances O2 diffusion from microvessels to mitochondria during exercise. This article is protected by copyright. All rights reserved.

  • 28.
    Carlström, Mattias
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi.
    Brown, Russell D.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi.
    Yang, T.
    Hezel, M.
    Larsson, Erik
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för immunologi, genetik och patologi, Molekylär och morfologisk patologi.
    Scheffer, P. G.
    Teerlink, T.
    Lundberg, J. O.
    Persson, A. Erik G.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi.
    L-arginine or tempol supplementation improves renal and cardiovascular function in rats with reduced renal mass and chronic high salt intake2013Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 207, nr 4, s. 732-741Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aim Early life reduction in nephron number and chronic high salt intake cause development of renal and cardiovascular disease, which has been associated with oxidative stress and nitric oxide (NO) deficiency. We investigated the hypothesis that interventions stimulating NO signalling or reducing oxidative stress may restore renal autoregulation, attenuate hypertension and reduce renal and cardiovascular injuries following reduction in renal mass and chronic high salt intake. Methods Male SpragueDawley rats were uninephrectomized (UNX) or sham-operated at 3weeks of age and given either a normal-salt (NS) or high-salt (HS) diet. Effects on renal and cardiovascular functions were assessed in rats supplemented with substrate for NO synthase (L-Arg) or a superoxide dismutase mimetic (Tempol). Results Rats with UNX+HS developed hypertension and displayed increased renal NADPH oxidase activity, elevated levels of oxidative stress markers in plasma and urine, and reduced cGMP in plasma. Histological analysis showed signs of cardiac and renal inflammation and fibrosis. These changes were linked with abnormal renal autoregulation, measured as a stronger tubuloglomerular feedback (TGF) response. Simultaneous treatment with L-Arg or Tempol restored cGMP levels in plasma and increased markers of NO signalling in the kidney. This was associated with normalized TGF responses, attenuated hypertension and reduced signs of histopathological changes in the kidney and in the heart. Conclusion Reduction in nephron number during early life followed by chronic HS intake is associated with oxidative stress, impaired renal autoregulation and development of hypertension. Treatment strategies that increase NO bioavailability, or reduce levels of reactive oxygen species, were proven beneficial in this model of renal and cardiovascular disease.

  • 29.
    Carlström, Mattias
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi.
    Sällström, Johan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi.
    Skott, Ole
    Larsson, Erik
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för genetik och patologi.
    Wåhlin, Nils
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi.
    Persson, A. Erik G.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi.
    Hydronephrosis causes salt-sensitive hypertension and impaired renal concentrating ability in mice2007Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 189, nr 3, s. 293-301Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aim: Hypertension is a common disease in the industrialized world and approximately 5% of all cases are secondary to kidney malfunction. We have recently shown that hydronephrosis due to partial unilateral ureteral obstruction (PUUO) causes salt-sensitive hypertension in rats. The mechanisms are still unclear, but appear to be intrarenal and primarily located to the diseased kidney. In the present study, we have developed a model for PUUO to study if hydronephrotic mice develop salt-sensitive hypertension.

    Methods: PUUO was created in 3-week-old mice (C57bl/6J). Blood pressure and heart rate were measured telemetrically in adult animals on normal and high salt diets. Metabolism cages were used to study the renal excretion of electrolytes and water. Plasma samples for renin analysis were collected and renal histological changes were evaluated.

    Results: All hydronephrotic animals developed salt-sensitive hypertension that correlated to the degree of hydronephrosis. In hydronephrotic animals, blood pressure increased from 114 ± 1 mmHg on normal salt diet to 120 ± 2 mmHg on high salt diet, compared with 103 ± 1 to 104 ± 1 in controls. Hydronephrotic animals showed increased diuresis and reduced ability to regulate electrolyte concentration. No differences in plasma renin concentration were found between the groups. The parenchymal weight and glomerular area of contralateral kidneys were significantly increased in the hydronephrotic animals. Histopathology of the hydronephrotic kidneys displayed areas with fibrosis, inflammation and glomerular changes.

    Conclusion: This study provides a model for PUUO in mice and demonstrates the presence of salt-sensitive hypertension and an impaired renal concentrating ability in mice which has not been described before.

  • 30.
    Carlström, Mattias
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi, Integrativ Fysiologi.
    Wåhlin, Nils
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi, Integrativ Fysiologi.
    Skott, Ole
    Persson, A. Erik G.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi, Integrativ Fysiologi.
    Relief of chronic partial ureteral obstruction attenuates salt-sensitive hypertension in rats2007Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 189, nr 1, s. 67-75Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aim: The incidence of hydronephrosis due to ureteropelvic junction obstruction is approx. 0.5%. During the last decade, the management of non-symptomatic hydronephrosis has become much more conservative, but the long-term physiological consequences of this policy are not clear. Previously, we have shown that animals with chronic partial unilateral ureteral obstruction develop salt-sensitive hypertension. In this study, the effects of ipsilateral and contralateral nephrectomy and ureterovesicostomy on blood pressure were studied in hydronephrotic animals.

    Methods: Partial unilateral ureteral obstruction was created in 3-week-old male Sprague–Dawley rats and blood pressure was measured telemetrically 4–6 weeks later during a normal and high salt diet before and after uninephrectomy or ureterovesicostomy. Plasma samples for renin assay were collected during both diets before and after ipsilateral nephrectomy.

    Results: All hydronephrotic animals developed salt-sensitive hypertension, of different degrees. Before nephrectomy the plasma renin concentration was significantly higher in the hydronephrotic animals than in controls (160 ± 15 μGU mL−1 vs. 96 ± 12 μGU mL−1, respectively), but after the ipsilateral nephrectomy no differences were found between the groups. In the hydronephrotic animals both ipsilateral nephrectomy and ureterovesicostomy reduced the blood pressure and salt-sensitivity but the former still differed significantly from the controls. In contralaterally, nephrectomized hydronephrotic animals the salt-sensitive hypertension became more pronounced.

    Conclusion: Hydronephrosis in rats causes salt-sensitive hypertension that can be markedly reduced by removing the hydronephrotic kidney or relieving the obstruction by ureterovesicostomy. The mechanisms appear to be intrarenal and primarily located in the diseased kidney, but a secondary mechanism is also present.

  • 31.
    Chaillou, Thomas
    et al.
    Département Environnements opérationnels, Institut de Recherche Biomédicale des Armées Antenne de la Tronche, La Tronche, France.
    Koulmann, N.
    Département Environnements opérationnels, Institut de Recherche Biomédicale des Armées Antenne de la Tronche, La Tronche, France; Ecole du Val-de-Grâce, Paris, France.
    Meunier, A.
    Département Environnements opérationnels, Institut de Recherche Biomédicale des Armées Antenne de la Tronche, La Tronche, France.
    Malgoyre, A.
    Département Environnements opérationnels, Institut de Recherche Biomédicale des Armées Antenne de la Tronche, La Tronche, France.
    Serrurier, B.
    Département Environnements opérationnels, Institut de Recherche Biomédicale des Armées Antenne de la Tronche, La Tronche, France.
    Beaudry, M.
    Laboratoire Réponses cellulaires et fonctionnelles à l'hypoxie, Université Paris, Sorbonne-Paris-Cité, France.
    Bigard, X.
    Département Environnements opérationnels, Institut de Recherche Biomédicale des Armées Antenne de la Tronche, La Tronche, France; Ecole du Val-de-Grâce, Paris, France.
    Effect of hypoxia exposure on the phenotypic adaptation in remodelling skeletal muscle submitted to functional overload2013Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 209, nr 4, s. 272-282Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aim: To determine whether hypoxia influences the phenotypic adaptation of skeletal muscle induced by mechanical overload.

    Methods: Plantaris muscles of female rats were submitted to mechanical overload following synergist ablation. After 3 days of overload, rats were exposed to either hypobaric hypoxia (equivalent to 5500 m) or normoxia. Muscles were collected after 5, 12 and 56 days of overload (i.e. after 3, 9 and 53 days of hypoxia). We determined the myosin heavy chain (MHC) distribution, mRNA levels of myocyte-enriched calcineurin-integrating protein 1 (MCIP1) to indirectly assess calcineurin activity, the changes in oxidative capacity from the activities of citrate synthase (CS) and cytochrome c oxidase (COX), and the expression of regulators involved in mitochondrial biogenesis (Pgc-1α, NRF1 and Tfam) and degradation (BNIP-3).

    Results: Hypoxia did not alter the fast-to-slow MHC shift and the increase in calcineurin activity induced by overload; it only transiently slowed down the overload-induced transition in MHC isoforms. Hypoxia similarly decreased CS and COX activities in overloaded and control muscles. Nuclear respiratory factor 1 (NRF1) and transcription factor A (Tfam) mRNA and BNIP-3 protein were not influenced by hypoxia in overloaded muscles, whereas Pgc-1α mRNA and protein contents did not correlate with changes in oxidative capacity.

    Conclusion: Hypoxia is not a critical stimulus to modulate the fast-to-slow MHC transition associated with overload. Thus, the impairment of the fast-to-slow fibre shift often observed during post-natal development in hypoxia could be explained by the lower voluntary locomotor activity associated with hypoxia. Hypoxia alters mitochondrial oxidative capacity, but this adaptive response is similar in overloaded and control muscles.

  • 32.
    Cheng, A
    et al.
    Karolinska Institutet, Stockholm, Sweden.
    Allodi, I
    Karolinska Institutet, Stockholm, Sweden.
    Chaillou, Thomas
    Karolinska Institutet, Stockholm, Sweden.
    Thams, S
    Karolinska Institutet, Stockholm, Sweden.
    Ivarsson, N
    Karolinska Institutet, Stockholm, Sweden.
    Schlittler, M
    Karolinska Institutet, Stockholm, Sweden.
    Lanner, J
    Karolinska Institutet, Stockholm, Sweden.
    Hedlund, E
    Karolinska Institutet, Stockholm, Sweden.
    Andersson, D
    Karolinska Institutet, Stockholm, Sweden.
    Increased fatigue resistance and preserved specific force in intact single muscle fibres from the SOD1G93A mouse model of ALS2017Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 219, nr S710, s. 17-17, artikkel-id P-28Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Introduction: Amyotrophic lateral sclerosis (ALS) is a motor neurone disease characterized by degeneration and loss of motor neurones, leading to severe muscle weakness and paralysis. Although motor neurone degeneration is already a well-characterized symptom that contributes to muscle weakness in the SOD1G93A mouse model of ALS, the purpose of the current study was to determine whether muscle weakness in ALS can be attributed to impaired intrinsic force generation in skeletal muscles of SOD1G93A mice.

    Methods: Experiments were performed on whole muscles and mechanically dissected intact single fibres from the flexor digitorum brevis (FDB) muscle of SOD1G93A mice at three age groups of 50, 125 and 150 days of age (P50, P125 and P150). Myoplasmic free [Ca2+] ([Ca2+]i) was measured using the fluorescent indicator, indo-1.

    Results: Motor neurone loss and decreased force were evident in whole FDB muscles of P125–150 mice. In the intact single muscle fibres however, specific force, tetanic [Ca2+]iand resting [Ca2+]i were similar in single FDB fibres from symptomatic P125–150 SOD1G93A and age-matched wild-type littermates. The most intriguing finding was a markedly greater fatigue resistance in single fibres from P125–150 SOD1G93A vs. wild-type mice, which was not present in asymptomatic young P50 SOD1G93A mice. No shift in fibre-type distribution was observed in whole FDB muscles to explain the increased fatigue resistance of single fibres from P125–150 SOD1G93A mice.

    Conclusion: These results support the hypothesis that muscle weakness in ALS is not attributed to intrinsicdefects in skeletal muscle fibre force generation.

  • 33.
    Claesson-Welsh, Lena
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för immunologi, genetik och patologi, Vaskulärbiologi.
    On the physiology of vascular permeability2015Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 215, s. 19-19Artikkel i tidsskrift (Annet vitenskapelig)
  • 34.
    Comasco, Erika
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap.
    Rangmar, J
    Univ Gothenburg, Dept Psychol, Gothenburg, Sweden.
    Eriksson, Ulf J.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi.
    Oreland, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap.
    Neurological and neuropsychological effects of low and moderate prenatal alcohol exposure2018Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 222, nr 1, artikkel-id e12892Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Several explanations for the diverse results in research on foetal alcohol spectrum disorders or alcohol-related neurodevelopmental disorder might be at hand: timing, amount and patterns of alcohol exposure, as well as complex epigenetic responses. The genetic background of the offspring and its interaction with other prenatal and post-natal environmental cues are likely also of importance. In the present report, key findings about the possible effects of low and moderate doses of maternal alcohol intake on the neuropsychological development of the offspring are reviewed and plausible mechanisms discussed. Special focus is put on the serotonergic system within developmental and gene-environment frameworks. The review also suggests guidelines for future studies and also summarizes some of to-be-answered questions of relevance to clinical practice. Contradictory findings and paucity of studies on the effects of exposure to low alcohol levels during foetal life for the offspring's neuropsychological development call for large prospective studies, as well as for studies including neuroimaging and multi-omics analyses to dissect the neurobiological underpinnings of alcohol exposure-related phenotypes and to identify biomarkers. Finally, it remains to be investigated whether any safe threshold of alcohol drinking during pregnancy can be identified.

  • 35.
    Cristea, Alexander
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap.
    Korhonen, Marko
    Häkkinen, Keijo
    Mero, Antti
    Alén, Markku
    Sipilä, Sarianna
    Viitasalo, Jukka
    Koljonen, Martti
    Suominen, Harri
    Larsson, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap.
    Effects of combined strength and sprint training on regulation of muscle contraction at the whole-muscle and single fibre levels in elite master sprinters2008Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 193, nr 3, s. 275-289Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    AIM: This study aims at examining the effects of progressive strength and sprint training on regulation of muscle contraction at the whole-muscle and single-fibre levels in older sprint-trained athletes. METHODS: Eleven men (52-78 years) were randomized to a training (EX, n = 7) or control (CTRL, n = 4) group. EX participated in a 20-week programme that combined sprint training with heavy and explosive strength exercises, while CTRL maintained their usual run-based training schedules. RESULTS: EX improved maximal isometric and dynamic leg strength, explosive jump performance and force production in running. Specific tension and maximum shortening velocity of single fibres from the vastus lateralis were not altered in EX or CTRL. Fibre type and myosin heavy chain isoform distributions remained unchanged in the two groups. There was a general increase in fibre areas in EX, but this was significant only in IIa fibres. The 10% increase in squat jump in EX was accompanied by a 9% increase in the integrated EMG (iEMG) of the leg extensors but the 21-40% increases in isometric and dynamic strength were not paralleled by changes in iEMG. CONCLUSION: Adding strength training stimulus to the training programme improved maximal, explosive and sport-specific force production in elite master sprinters. These improvements were primarily related to hypertrophic muscular adaptations.

  • 36. Danielsson, T
    et al.
    Fredriksson, L
    Jansson, Leif
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi.
    Henriksnäs, Johanna
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi.
    Resistin increases islet blood flow and decreases subcutaneous adipose tissue blood flow in anaesthetized rats2009Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 195, nr 2, s. 283-288Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    AIM: Resistin is an adipokine which has been suggested to participate in the induction of insulin resistance associated with type 2 diabetes. The aim of the present study was to investigate whether acute administration of resistin influences tissue blood perfusion in rats. METHODS: Resistin was administered as an intravenous infusion of 7.5 microg h(-1) (1.5 mL h(-1)) for 30 min to rats anaesthetized with thiobutabarbital. A microsphere technique was used to estimate the blood flow to six different depots of white adipose tissue (WAT), brown adipose tissue (BAT), as well as to the pancreas, islets, duodenum, colon, kidneys, adrenal glands and liver. RESULTS: Resistin administration led to an increased blood flow to the pancreas and islets and a decrease in subcutaneous WAT and BAT. Intra-abdominal white adipose tissue blood flow and that to other organs were not affected. CONCLUSION: Acute administration of resistin markedly affects the blood perfusion of both the pancreas and subcutaneous white adipose tissue depots. At present it is unknown whether resistin exerts a direct effect on the vasculature, or works through local or systemic activation of endothelial cells and/or macrophages. The extent to which this might contribute to the insulin resistance caused by resistin is yet unknown.

  • 37.
    Druzin, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB).
    Setting neuronal chloride gradient: a new role for extracellular matrix2015Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 215, s. 45-45Artikkel i tidsskrift (Annet vitenskapelig)
  • 38.
    Ekenros, L.
    et al.
    Karolinska Inst, Div Physiotherapy, Dept Neurobiol Care Sci & Soc, Huddinge, Sweden..
    Papoutsi, Zoi
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Centrum för klinisk forskning i Sörmland (CKFD). Karolinska Inst, Novum, Dept Biosci & Nutr, Huddinge, Sweden..
    Friden, C.
    Karolinska Inst, Div Physiotherapy, Dept Neurobiol Care Sci & Soc, Huddinge, Sweden.;St Erik Primary Hlth Care Ctr, Acad Primary Hlth Care Ctr, Stockholm, Sweden..
    Wright, K. Dahlman
    Karolinska Inst, Novum, Dept Biosci & Nutr, Huddinge, Sweden..
    Hirschberg, A. Linden
    Karolinska Inst, Div Obstet & Gynecol, Dept Womens & Childrens Hlth, Stockholm, Sweden..
    Expression of sex steroid hormone receptors in human skeletal muscle during the menstrual cycle2017Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 219, nr 2, s. 486-493Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aim: Variations in sex hormone levels during the menstrual cycle may affect neuromuscular performance and the risk of sustaining musculoskeletal injury in women. The aim of this study was to investigate mRNA and protein levels for sex steroid hormone receptors in skeletal muscle in three distinct phases of the menstrual cycle. Methods: Fifteen, healthy women with regular menstrual cycles participated in the study. Muscle biopsies from the vastus lateralis were obtained in three hormonally verified phases of the menstrual cycle for each individual, that is the follicular phase, the ovulatory phase and the luteal phase. mRNA and protein levels of oestrogen (ER and ER), progesterone (PR) and androgen (AR) receptors were analysed. Results: There was an overall significant variation in mRNA and protein levels of ER and PR across the menstrual cycle. mRNA and protein levels of ER were highest in the follicular phase when oestradiol levels were low, whereas protein levels of PR were highest in the luteal phase when progesterone levels were high. mRNA levels of PR were highest in the ovulatory phase. No significant variation in AR levels was detected across the menstrual cycle. ER levels were very low in all three phases of the menstrual cycle. Conclusion: Significant variations in mRNA and protein levels of ER and PR were detected in skeletal muscle during three confirmed phases of the menstrual cycle. These results may have an impact on effects of muscular training and sports injuries in women.

  • 39.
    Ekholm, Marie
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Fysiologi.
    Johansson, Lisa
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Fysiologi.
    Kukkonen, Jyrki P.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Fysiologi.
    Rapid and easy semi-quantitative evaluation method for diacylglycerol and inositol-1,4,5-trisphosphate generation in orexin receptor signalling2010Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 198, nr 3, s. 387-392Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aim: Fluorescent protein-based indicators have enabled measurement of intracellular signals previously nearly inaccessible for studies. However, indicators showing intracellular translocation upon response suffer from serious limitations, especially the very time-consuming data collection. We therefore set out in this study to evaluate whether fixing and counting cells showing translocation could mend this issue.

    Methods: Altogether three different genetically encoded indicators for diacylglycerol and inositol-1,4,5-trisphosphate were transiently expressed in Chinese hamster ovary cells stably expressing human OX1 orexin receptors. Upon stimulation with orexin-A, the cells were fixed with six different protocols.

    Results: Different protocols showed clear differences in their ability to preserve the indicator’s localization (i.e. translocation after stimulus) and its fluorescence, and the best results for each indicator were obtained with a different protocol. The concentration

    Conclusion: The counting method, as used here, works at single time point and looses the single-cell-quantitative aspect. However, it also has some useful properties. First, it easily allows processing of a 100- to 1000-fold higher cell numbers than real-time imaging producing statistically consistent population-quantitative data much faster. Secondly, it does not require expensive real-time imaging equipment. Fluorescence in fixed cells can also be quantitated, though this analysis would be more time-consuming than cell counting. Thirdly, in addition to the quantitative data collection, the method could be applied for identifying responsive cells. This might be very useful in identification of e.g. orexin-responding neurones in a large population of non-responsive cells in primary cultures.

  • 40.
    Elinder, Fredrik
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelning för neurobiologi. Linköpings universitet, Medicinska fakulteten.
    Alpha and omega in potassium-channel opening2019Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 225, nr 2, artikkel-id e13240Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    n/a

    Fulltekst tilgjengelig fra 2020-12-16 15:11
  • 41.
    Esbjörnsson, M
    et al.
    Karolinska Institutet.
    Rundqvist, H C
    Karolinska Institutet.
    Mascher, H
    Karolinska Institutet.
    Österlund, T
    Karolinska Institutet.
    Rooyackers, O
    Karolinska Institutet.
    Blomstrand, Eva
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Eva Blomstrands forskningsgrupp.
    Jansson, E
    Karolinska Institutet.
    Sprint exercise enhances skeletal muscle p70S6k phosphorylation and more so in women than in men.2012Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 205, nr 3, s. 411-22Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    AIM: Sprint exercise is characterized by repeated sessions of brief intermittent exercise at a high relative workload. However, little is known about the effect on mTOR pathway, an important link in the regulation of muscle protein synthesis. An earlier training study showed a greater increase in muscle fibre cross-sectional area in women than men. Therefore, we tested the hypothesis that the activation of mTOR signalling is more pronounced in women than in men. Healthy men (n=9) and women (n=8) performed three bouts of 30-s sprint exercise with 20-min rest in between.

    METHODS: Multiple blood samples were collected over time, and muscle biopsy specimens were obtained at rest and 140 min after the last sprint.

    RESULTS: Serum insulin increased by sprint exercise and more so in women than in men [gender (g) × time (t)]: P=0.04. In skeletal muscle, phosphorylation of Akt increased by 50% (t, P=0.001) and mTOR by 120% (t, P=0.002) independent of gender. The elevation in p70S6k phosphorylation was larger in women (g × t, P=0.03) and averaged 230% (P=0.006) as compared to 60% in men (P=0.04). Phosphorylation rpS6 increased by 660% over time independent of gender (t, P=0.003). Increase in the phosphorylation of p70S6k was directly related to increase in serum insulin (r=0.68, P=0.004).

    CONCLUSION: It is concluded that repeated 30-s all-out bouts of sprint exercise separated by 20 min of rest increases Akt/mTOR signalling in skeletal muscle. Secondly, signalling downstream of mTOR was stronger in women than in men after sprint exercise indicated by the increased phosphorylation of p70S6k.

  • 42.
    Fernandez-Gonzalo, R.
    et al.
    Karolinska Inst, Dept Physiol & Pharmacol, S-17177 Stockholm, Sweden.
    Lundberg, Tommy R.
    Mittuniversitetet, Fakulteten för humanvetenskap, Avdelningen för hälsovetenskap.
    Tesch, Per A.
    Mittuniversitetet, Fakulteten för humanvetenskap, Avdelningen för hälsovetenskap. Karolinska Inst, Dept Physiol & Pharmacol, S-17177 Stockholm, Sweden.
    Acute molecular responses in untrained and trained muscle subjected to aerobic and resistance exercise training versus resistance training alone2013Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 209, nr 4, s. 283-294Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    AimThis study assessed and compared acute muscle molecular responses before and after 5-week training, employing either aerobic (AE) and resistance exercise (RE) or RE only. MethodsTen men performed one-legged RE, while the contralateral limb performed AE followed by RE 6h later (AE+RE). Before (untrained) and after (trained) the intervention, acute bouts of RE were performed with or without preceding AE. Biopsies were obtained from m. vastus lateralis of each leg pre- and 3h post-RE to determine mRNA levels of VEGF, PGC-1, MuRF-1, atrogin-1, myostatin and phosphorylation of mTOR, p70S6K, rpS6 and eEF2. ResultsPGC-1 and VEGF expression increased (P<0.05) after acute RE in the untrained, but not the trained state. These markers showed greater response after AE+RE than RE in either condition. Myostatin was lower after AE+RE than RE, both before and after training. AE+RE showed higher MuRF-1 and atrogin-1 expression than RE in the untrained, not the trained state. Exercise increased (P<0.05) p70S6K phosphorylation both before and after training, yet this increase tended to be more prominent for AE+RE than RE before training. Phosphorylation of p70S6K was greater in trained muscle. Changes in these markers did not correlate with exercise-induced alterations in strength or muscle size. ConclusionConcurrent exercise in untrained skeletal muscle prompts global molecular responses consistent with resulting whole muscle adaptations. Yet, training blunts the more robust anabolic response shown after AE+RE compared with RE. This study challenges the concept that single molecular markers could predict training-induced changes in muscle size or strength.

  • 43.
    Flemström, Gunnar
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Fysiologi.
    Bengtsson, Magnus Wilhelm
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Fysiologi.
    Mäkelä, Kari Antero
    Inst. of Biomedicine, Div. of Physiology, Oulu Univ., Oulu, Finland.
    Herzig, Karl-Heinz
    Inst. of Biomedicine, Div. of Physiology, Oulu Univ., Oulu, Finland.
    Effects of short-term food deprivation on orexin-A-induced intestinal bicarbonate secretion in comparison with related secretagogues2010Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 198, nr 3, s. 373-380Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Studies of gastrointestinal physiology in humans and intact animals are usually conducted after overnight fast. We have compared effects of orexin-A, vasoactive intestinal polypeptide (VIP), melatonin, serotonin, uroguanylin, ghrelin and prostaglandin E2 (PGE2) on duodenal bicarbonate secretion in fed and overnight fasted animals. This review is a summary of our findings. Secretagogues  were administered by intra-arterial infusion or luminally (PGE2) Enterocyte intracellular calcium ([Ca2+]i) signaling was studied by fluorescence imaging. Total RNA was extracted, reverse transcripted to cDNA and expression of orexin receptors measured by quantitative real-time PCR.

    Orexin-A stimulates the duodenal secretion in continuously fed animals but not in food deprived animals. Similarly, short fasting causes a 100-fold decrease  of the amount of the muscarinic agonist bethanechol required for stimulation of secretion. In contrast, fasting does not affect secretory responses to intra-arterial VIP, melatonin, serotonin, uroguanylin and ghrelin, or that to luminal PGE2. Orexin-A induces [Ca2+]i signaling in enterocytes from fed rats but no significant [Ca2+]i responses occurs in enterocytes from fasted animals. In addition, overnight fasting decreases the expression of mucosal and enterocyte orexin receptors.

    Short food deprivation thus decreases duodenal expression of orexin receptors and abolishes the secretory response to orexin-A as well as orexin-A induced [Ca2+]i signaling. Fasting, furthermore, decreases mucosal sensitivity to bethanechol. The absence of declines in secretory responses to other secretagogues tested is strong evidence that short fasting does affect not the secretory capacity of the duodenal mucosa in general. Studies of intestinal secretion require particular evaluation with respect to feeding status.

  • 44.
    Flemström, Gunnar
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Fysiologi.
    Mäkelä, Kari
    University of Oulu, Oulu, Finland.
    Purhonen, Anna-Kaisa
    University of Oulu, Oulu, Finland.
    Sjöblom, Markus
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Fysiologi.
    Jedstedt, Gunilla
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Fysiologi.
    Walkowiak, Jan
    University of Medical Sciences, Poznan, Poland.
    Herzig, Karl-Heinz
    University of Oulu, Oulu, Finland.
    Apelin stimulation of duodenal bicarbonate secretion: feeding-dependent and mediated via apelin-induced release of enteric cholecystokinin2011Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 201, nr 1, s. 141-150Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aim: Apelin peptides is the endogenous ligand of the G protein-coupled receptor APJ. Proposed actions include involvement in control of cardiovascular functions, appetite and body metabolism. We have investigated effects of apelin peptides on duodenal bicarbonate secretion in vivo and the release of cholecystokinin (CCK) from acutely isolated mucosal cells and the neuroendocrine cell line STC-1. Methods: Lewis x Dark Agouti rats had free access to water and, unless fasted overnight, free access  to food. A segment of proximal duodenum was cannulated in situ in anesthetized animals. Mucosal bicarbonate secretion was titrated (pH stat) and apelin was administered to the duodenum by close intra-arterial infusion. Total RNA was extracted from mucosal specimens, reverse transcripted to cDNA and expression of the APJ receptor measured by quantitative real-time PCR. Apelin-induced release of CCK was measured using (i) cells prepared from proximal small intestine, and (ii) STC-1 cells. Results: Even the lowest dose of apelin-13 (6 pmol kg-1 h-1) caused a significant rise in bicarbonate secretion. Stimulation occurred only in continuously fed animals and even a 100-fold greater dose (600 pmol kg-1 h-1) of apelin was without effect in overnight food deprived animals. Fasting also induced a 8-fold decrease  in the expression of APJ receptor mRNA. Apelin induced significant release of CCK from both mucosal and STC-1 cells, and the CCKA receptor antagonist devazepide abolished bicarbonate secretory responses to apelin. Conclusions: Apelin-induced stimulation of duodenal electrolyte secretion is feeding dependent and mediated by local mucosal release of CCK

     

  • 45.
    Folkesson, Mattias
    et al.
    Örebro universitet, Hälsoakademin.
    Mackey, A. L.
    Institute of Sports Medicine, Bispebjerg Hospital and Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
    Holm, L.
    Institute of Sports Medicine, Bispebjerg Hospital and Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
    Kjaer, M.
    Institute of Sports Medicine, Bispebjerg Hospital and Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
    Paulsen, G.
    Department of Sports Medicine, Norwegian School of Sports Sciences, Oslo, Norway.
    Raastad, T.
    Department of Sports Medicine, Norwegian School of Sports Sciences, Oslo, Norway.
    Henriksson, J.
    Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
    Kadi, Fawzi
    Örebro universitet, Institutionen för hälsovetenskap och medicin.
    Immunohistochemical changes in the expression of HSP27 in exercised human vastus lateralis muscle2008Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 194, nr 3, s. 215-222Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aim: The role of HSP27 in the adaptive process of skeletal muscle to exercise, especially in humans, is not well understood. The objective of this study was to investigate immunohistochemical changes in HSP27 expression in human vastus lateralis muscle following resistance and endurance exercises.

    Methods: Two different exercise protocols were used: (1) one-leg ergometer cycling (EC, n = 6) consisting of two 30-min bouts at 40% and 75% of peak oxygen uptake, respectively, and (2) leg extension resistance exercise (RE, n = 9) including 10 sets of eight repetitions at a load corresponding to 70% of one maximal repetition (1RM). Immunohistochemistry using specific monoclonal antibodies was used to determine the location of HSP27 protein in muscle biopsies from human vastus lateralis.

    Results: Our results show that RE, but not EC, induced a significant appearance of scattered accumulations of HSP27 protein in muscle fibres from five of nine subjects. The number of fibres with accumulation of HSP27 in RE ranged from 0% to 32% with a mean of 6.3% of the total number of fibres.

    Conclusion: We conclude that this rapid HSP27 protein relocation after RE is an important player in the cellular remodelling of human muscle fibres in response to exercise involving high-force contractions, but not in response to endurance exercises.

  • 46.
    Folkesson, Mattias
    et al.
    Örebro universitet, Institutionen för hälsovetenskap och medicin.
    Mackey, Abigail L.
    Department of Orthopaedic Surgery M, Faculty of Health Sciences, Institute of Sports Medicine, Bispebjerg Hospital, Copenhagen, Denmark; Centre for Healthy Ageing, University of Copenhagen, Copenhagen, Denmark.
    Langberg, Henning
    Department of Orthopaedic Surgery M, Faculty of Health Sciences, Institute of Sports Medicine, Bispebjerg Hospital, Copenhagen, Denmark; Centre for Healthy Ageing, University of Copenhagen, Copenhagen, Denmark.
    Oskarsson, Eva
    Örebro universitet, Institutionen för hälsovetenskap och medicin.
    Piehl-Aulin, Karin
    School of Health and Medical Sciences, Örebro University, Örebro, Sweden; Department of Clinical Sciences, Danderyds Hospital, Karolinska Institutet, Stockholm, Sweden.
    Henriksson, Jan
    Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
    Kadi, Fawzi
    Örebro universitet, Institutionen för hälsovetenskap och medicin.
    The expression of heat shock protein in human skeletal muscle: effects of muscle fibre phenotype and training background2013Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 209, nr 1, s. 26-33Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aim: Exercise-induced adaptations of skeletal muscle are related to training mode and can be muscle fibre type specific. This study aimed to investigate heat shock protein expression in type I and type II muscle fibres in resting skeletal muscle of subjects with different training backgrounds.

    Methods: Three groups of subjects were included: healthy active not engaged in any training programme (ACT, n = 12), resistance trained (RES, n = 6) and endurance trained (END, n = 8). Biopsies were obtained from vastus lateralis, and immunohistochemistry was performed using monoclonal antibodies against myosin heavy chain I and IIA, αB-crystallin, HSP27, HSP60 and HSP70.

    Results: In ACT and RES, but not in END, a fibre type–specific expression with higher staining intensity in type I than type II fibres was seen for αB-crystallin. The opposite (II > I) was found for HSP27 in subjects from ACT (6 of 12 subjects) and RES (3 of 6), whereas all subjects from END displayed uniform staining. HSP60 showed no fibre-specific expression. HSP70 displayed a fibre-specific expression pattern (I > II) in ACT (4 of 12), but not in END or RES.

    Conclusion: This study shows that the level of expression of the different HSPs in human skeletal muscle is influenced by muscle fibre phenotype. The fibre type–specific expression of HSP70 is influenced by resistance and endurance training, whereas those of αB-crystallin and HSP27 is influenced only by endurance training, suggesting the existence of a training-modality-specific action on the adaptive processes including heat shock proteins in human skeletal muscle.

  • 47.
    Formenti, F.
    et al.
    Kings Coll London, London, England.;Univ Oxford, Oxford, England..
    Bommakanti, N.
    Univ Oxford, Oxford, England..
    Chen, R.
    Univ Oxford, Oxford, England..
    Cronin, J.
    Kings Coll London, London, England..
    McPeak, H.
    Univ Oxford, Oxford, England..
    Holopherne-Doran, D.
    Univ Bristol, Bristol, Avon, England..
    Hedenstierna, Göran
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Klinisk fysiologi. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Hahn, C.
    Univ Oxford, Oxford, England..
    Larsson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Farmery, A.
    Univ Oxford, Oxford, England..
    Alveolar oxygen respiratory oscillations measured in arterial blood2017Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 221, nr SI, s. 20-20Artikkel i tidsskrift (Annet vitenskapelig)
  • 48. Franzen, S.
    et al.
    Palm, Fredrik
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi.
    Endothelin receptor A blockade normalizes kidney tissue hypoxia in type-1 diabetic rats2014Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 211, nr S696, s. 79-79, artikkel-id P31Artikkel i tidsskrift (Annet vitenskapelig)
  • 49.
    Friederich, Malou
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi, Integrativ Fysiologi.
    Persson, Patrik
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi, Integrativ Fysiologi.
    Hansell, Peter
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi, Integrativ Fysiologi.
    Palm, Fredrik
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi, Integrativ Fysiologi.
    Deletion of Uncoupling Protein-2 reduces renal mitochondrial leak respiration, intrarenal hypoxia and proteinuria in a mouse model of type 1 diabetes2018Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 223, nr 4, artikkel-id e13058Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    AimUncoupling protein-2 (UCP-2) can induce mitochondrial uncoupling in the diabetic kidney. Although mitochondrial uncoupling reduces oxidative stress originating from the mitochondria and can be regarded as a protective mechanism, the increased oxygen consumption occurring secondarily to increased mitochondria uncoupling, that is leak respiration, may contribute to kidney tissue hypoxia. Using UCP-2(-/-) mice, we tested the hypothesis that UCP-2-mediated leak respiration is important for the development of diabetes-induced intrarenal hypoxia and proteinuria. MethodsKidney function, invivo oxygen metabolism, urinary protein leakage and mitochondrial function were determined in wild-type and UCP-2(-/-) mice during normoglycaemia and 2weeks after diabetes induction. ResultsDiabetic wild-type mice displayed mitochondrial leak respiration, pronounced intrarenal hypoxia, proteinuria and increased urinary KIM-1 excretion. However, diabetic UCP-2(-/-) mice did not develop increased mitochondrial leak respiration and presented with normal intrarenal oxygen levels, urinary protein and KIM-1 excretion. ConclusionAlthough functioning as an antioxidant system, mitochondria uncoupling is always in co-occurrence with increased oxygen consumption, that is leak respiration; a potentially detrimental side effect as it can result in kidney tissue hypoxia; an acknowledged unifying pathway to nephropathy. Indeed, this study demonstrates a novel mechanism in which UCP-2-mediated mitochondrial leak respiration is necessary for the development of diabetes-induced intrarenal tissue hypoxia and proteinuria.

  • 50.
    Frithiof, Robert
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    Toll-like receptor 4 in sepsis-induced renal failure2014Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 211, nr S696, s. 39-39, artikkel-id 7:3Artikkel i tidsskrift (Annet vitenskapelig)
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