Women with polycystic ovary syndrome (PCOS) have an increased risk of developing cardiovascular disease (CVD). Metabolic syndrome predominate which may lead to impaired insulin sensitivity and development of type II diabetes and hypertension. Endothelial dysfunction together with pro-inflammatory, pro-thrombotic and pro-oxidant environment serves as initial phase for CVD complications. The research group performs functional studies on isolated arteries with focus on endothelium dependent relaxation from PCOS women and age matched controls and the aim of the presented project was to compare markers for endothelial dysfunction using immunohistochemistry (IHC). Small arteries were isolated from subcutaneous fat biopsies from patients and controls and fixed in O.C.T. compound (-70C dry ice). The biopsies were sectioned in 8µm thin slices for further staining with primary antibodies, DAB as a chromogen and Mayer´s Hematoxylin. The primary antibody was selected for endothelial cell adhesion molecules PECAM-1, P-selectin, vWF and VCAM-1.    There was a tendency for stronger expression of P-selectin in arteries from PCOS women compared with controls, while in the controls a tendency was seen towards stronger expression of VCAM-1 and a weaker staining for vWF if compared with PCOS. There was no obvious difference for other stained markers between the groups. There were differences between tested markers in control groups and the PCOS women whit IHC staining as well as earlier functional tests. Tested markers reflected that endothelial dysfunction were expressed in the endothelium of isolated arteries from PCOS and control women, however further functional studies and IHC studies were warranted to quantify their contribution.