Sex steroids and the endothelium.

Gonadal steroids clearly influence the course of atherosclerotic cardiovascular disease in women. This observation has suggested that these hormones have beneficial effects on the physiology of the vascular wall. Increased arterial vascular caliber after estrogen treatment, decreased lipid levels in subjects receiving hormone replacement therapy, and the markedly decreased extent of atherosclerotic plaque formation in young women as compared with young men support a cardioprotective effect of ovarian steroids. Generally, it appears that the effects of 17beta-estradiol are particularly beneficial, and the mechanism of action is targeted largely to the endothelial cell. This review describes the evidence for positive effects of estrogens on endothelial cell biology and considers potential mechanisms for estrogen actions on endothelial cell signal transduction.