Ovarian hormones and the circulation.

Ovarian steroids have effects on blood circulation involving the mechanisms which control blood flow and the changes that occur in the pathogenesis of atherosclerosis. Estrogens appear to protect women from cardiovascular disease through their effects on lipid metabolism as well as more direct effects on arterial walls which appear to inhibit atherosclerotic plaque formation. There is increasing evidence that estrogen replacement after menopause can markedly reduce female mortality due to vascular disease. Effects of hormone imbalance and deficiency on vasomotor control are clinically significant and hormone treatment appears to be effective in the management of a variety of conditions due to abnormal blood flow including vasomotor instability, migraine, vaginal dryness and, perhaps, some forms of angina. Most review articles have focused on the effects of ovarian steroids and lipid metabolism as well as the findings of recent epidemiologic studies. This is understandable as those investigations have proved so valuable in understanding the protective effects of estrogens. The present discussion, in contrast, focuses on the effects of ovarian steroids, estrogens in particular, on circulatory mechanisms. At the present time there is increasing interest in these studies. Findings thus far appear to contribute to understanding estrogen cardioprotection and also raise awareness of a variety of clinical conditions in which estrogen treatment could be indicated because of its effects on circulation.