Gender-related differences in vascular smooth muscle cell proliferation: implications for prevention of atherosclerosis

Premenopausal women have a significant reduction in coronary artery disease compared to age-matched males. Little is known about the mechanism underly ing this cardioprotective effect of estrogen. Contradictory evidence has be en published and our lack of basic understanding of hormone interactions an d bioavailability of different estrogens prevents definitive interpretation of these data. We demonstrate gender-specific effects in the proliferation of coronary artery vascular smooth muscle cells obtained from a sexually m ature animal model. Vascular smooth muscle cells are an integral component of the atherosclerotic plaque, and inhibition of cell proliferation by estr ogen may be one mechanism by which estrogen exerts its cardioprotective eff ect. Various types of estrogen may also have different mechanistic actions on the vascular system. No differences are demonstrated in overall estradio l binding in vascular smooth muscle cells obtained from male or female anim als; however, differences in c-jun, c-fos and TIEG gene expression were gen der related. Inhibition of vascular smooth muscle cell proliferation may ha ve important implications in the prevention of atherosclerotic disease and these studies may provide evidence for the cardioprotective effect of estro gen.