Non-genomic vascular actions of female sex hormones: Physiological implications and signalling pathways

1. Epidemiological studies indicate a lower incidence of coronary heart disease in premenopausal women compared with age-matched men and post-menopausal women. Accumulating evidence suggests that this cardiovascular protection observed in premenopausal women is at least partially attributed to the direct action of oestrogens on the vascular system. 2. Research focused on vascular actions of 17 beta-oestradiol indicates that this female sex hormone favourably modulates vascular reactivity at physiological concentrations. The vascular actions of 17 beta-oestradiol appear independent of its genomic actions. Both endothelium-dependent and -independent signalling cascades have been implicated in the vascular effects of 17 beta-oestradiol. 3. However, clinical trials on hormone-replacement therapy argue against a role of oestrogens in preventing the development of coronary heart disease. Supplementation with oestrogen is also complicated with the increased risk of breast and endometrial cancer. Hence, a better understanding of the vascular actions of 17 beta-oestradiol will serve to enhance our understanding of its role in coronary heart disease.