Expression of cyclo-oxygenase-2 in human atherosclerotic carotid arteries.

OBJECTIVES

the preventive effect of acetylsalicylic acid in cardiovascular disease may be due to inhibition of platelet aggregation mediated by COX-1, but may in addition be due to anti-inflammatory effects by inhibition of COX-2. The objective of this study was to analyse the expression of COX-1 and COX-2 in atherosclerotic and healthy vascular walls.

DESIGN

the expression COX-1 and COX-2 was analysed in biopsies from human atherosclerotic carotid arteries and from healthy mammary arteries and saphenous veins.

MATERIALS

vascular biopsies were obtained from patients undergoing carotid endarterectomy or coronary bypass surgery.

METHODS

RT-PCR was used for mRNA analysis and for localization of proteins we used immunohistochemistry.

RESULTS

COX-2 was found in atherosclerotic plaques: in macrophages, in some smooth muscle cells and in endothelial cells of small vessels in the lesions. In non-atherosclerotic blood vessels, COX-2 was detected in the endothelium of the vasa vasorum in the adventitia. COX-1 was found in the endothelium in healthy and in atherosclerotic vessels.

CONCLUSIONS

the expression of COX-2 by inflammatory and vascular cells in atherosclerotic arteries suggests that products of this enzyme may be important in the pathogenesis of atherosclerosis.