Estrogen attenuates cadiovascular responses to psychological stress induced by environmental change

Abstract

Estrogen is believed to play a cardiovascular protective role. Moreover, an exaggerated cardiovascular response to psychological stress is thought to be an independent risk factor of cardiovascular disease. Therefore, cardiovascular protection by estrogen may involve its effects on cardiovascular responses to psychological stress. We assessed a hypothesis that estrogen has the beneficial effect of suppressing stress-induced cardiovascular responses in ovariectomized rat model of menopause or premenopausal and postmenopausal women. In the animal experiment, we showed that chronic estrogen replacement could suppress cardiovascular and catecholamine responses to psychological stresses evoked by environmental changes in ovariectomized rats. Moreover, this effect of estrogen was mediated at least partly by an over-expression of endothelial nitric oxide synthase in peripheral vessels or nitric oxide-producing neuronal activation in paraventricular hypothalamic nucleus. In the human experiment, the mental, but not physical, stress induced sustained diastolic blood pressure elevation in postmenopausal women, accompanied by an enhanced generation of oxidative stress. These findings suggest that estrogen attenuates cardiovascular responses to psychological stress. [J Physiol Sci. 2007;57 Suppl:S53]