مقايسه اثرات 17 - بتا استراديول و جنيستيين در روي شريان آيورت رت و وريد سافن انسان

Comparative effect of genistein and 17 p-estradiol on human saphenous vein and rat aorta

Comparing with age matched men the incidence of cardiovascular disease in fertiling women and menopause women who take estrogen is low.This finding suggest a protective effect for estrogen in cardiovascular system. Previous studies demonstrated the acute vasorelaxant effect of 17(Beta)-estradiol. This acute relaxing effect of estrogen is independent of endothelium, prostaglandin production and NO synthesis. Genistein is a plant derived isoflavone estrogen which originates mainly from soybean. The present study was carried out to investigate the acute vasorelaxant effect of genistein on isolated rat aorta and human saphenous vein, and to compare these effects with those of 17(Beta)~estradiol Rigs of rat (Wistar 250-300 g) aorta and human saphenous vein with 3-5 mm length were prepared and equilibrated in Krebsʹ solution under 2 g tension (37 oC ; 95% O2; 5% C02) for 60 min. In the various experiments, the vascular rings were contracted with prostaglandin F2(Alfa) (10(Gama)M), or potassium chloride (80 mM). When contraction was stable 17(Beta)~estradiol or genistein was applied for 40 minutes. Relaxation was expressed as % reversal of contraction induced by vasoactive agents. Denuding the endothelium of aortic rings or incubating them with N-nitro-L-arginine methyl ester, indomethacin did not alter vasorelaxant effect of genistein significantly. Therefore, it would suggest that this acute relaxing effect of genistein, similar to that of 17p-estradiol is independent of endothelium, NO synthesis and prostaglandin production. Acute relaxant effects of genistein (20(Gama)M) (100.0±0.0,n=6) on rat aortic rings contracted by prostaglandin F2(Alfa) was significantly greater than 17(Beta)-estradiol (20(Gama)iM) induced relaxation (56,7±3.5,n=ll), but relaxant effect of genistein (25.9±6.2,n=6) on rat aortic rings contracted by potassium chloride was significantly smaller than 17(Beta)~estradiol induced relaxation (64.4±2.4,n=14) (PO.05). Acute relaxant effects of genistein (91.5±4.9,n=6) on human saphenous vein contacted by prostaglandin F2(Alfa) was significantly greater than 17(Beta)-estradiol-induced relaxation (73.2±10.1,n=6) (P<0.05). From the present results it could be suggested that the plant derived estrogen, genistein, has relaxant effect similar to that of 17(Beta)-estradiol and may be a useful alternative in clinical applications of 17(Beta)-estradiol.