Acute responses to phytoestrogens in small arteries from men with coronary heart disease.
ABSTRACT The aim of this study was to investigate acute vasodilator responses to phytoestrogens and selective estrogen receptor-alpha (ERalpha) agonist in isolated small arteries from men with established coronary heart disease (CHD) and with a history of myocardial infarction versus healthy male control subjects. As to methodology, small arteries obtained from subcutaneous fat biopsies and mounted on a wire myograph were preconstricted with norepinephrine, and dilator responses to increasing nanomolar-micromolar concentrations of the phytoestrogens resveratrol and genistein (predominantly ERbeta agonists) and to propyl-[1H]-pyrazole-1,3,5-triyl-trisplenol (PPT, a selective ERalpha agonist) were determined. These were compared with responses to reference compound 17beta-estradiol (17beta-E2). Concentration-response curves were constructed before and after nitric oxide (NO) synthase inhibition with Nomega-nitro-L-arginine methyl ester. As a result, relaxation induced by the investigated compounds was similar in men with CHD and control men, but in both groups PPT and genistein-induced relaxation was greater than that of resveratrol and 17beta-E2. NO contributed to both phytoestrogens and PPT-induced relaxation but not to 17beta-E2 responses in arteries from control men. This NO-mediated component of relaxation was absent in arteries from men with established CHD. In conclusion, phytoestrogens, at concentrations achievable by ingestion of phytoestrogen-rich food products, evoke dilatation ex vivo of small peripheral arteries from normal men and those with established CHD. The contribution of NO to dilatory responses by these compounds is pertinent to arteries from control males, whereas other NO-independent dilatory mechanism(s) are involved in arteries from CHD.
Article: Gender and the endothelium.[show abstract] [hide abstract]
ABSTRACT: The understanding of the basis of gender differences in vascular function is of critical importance to establish gender targeted interventions in cardiovascular medicine. In this review we concentrate on the central role of the endothelium in respect to gender differences in cardiovascular physiology and pathophysiology. The role of estrogen and its receptors is introduced not only as key players in gender-related differences in incidence of cardiovascular abnormalities but also in endothelium-dependent maintenance of vascular tone through the release of endothelium-derived vasodilators and vasoconstrictors. An improved understanding of the distinct processes that confer vascular maintenance in women and men will help to develop new treatment alternatives and improve the use of existing drugs.Pharmacological reports: PR 60(1):49-60. · 2.44 Impact Factor