Efeito do relaxamento induzido por diosgenina em artéria mesentérica de rato após administração de 17-β estradiol.

Abstract

Cardiovascular disease is a major cause of morbidity and mortality in post - menopausal women, estrogen depletion in particular 17 - β estradiol a conditioning factor.Currently researchers have attempted, in studies with phytoestrogens, an alternative to impro ve the treatment of this illness, since hormone replacement therapy harms to patients with breast or uterine cancer. Among various existing phytoestrogens tried to assess the cardiovascular activity of diosgenin, found in species of the genus Dioscorea tha t has similar structure to estradiol and phytoestrogen is used for large scale synthesis of various steroid hormones. The purpose of this study was to investigate whether the relaxing effect induced by diosgenin, would be altered by estradiol and verify wh ether diosgenin and estradiol would modulate the basal tonus of mesenteric rings.To do this were used the superior mesenteric artery, isolated from Wistar rats, then they were cut into rings and putted inside a system of tanks for isolated organs. Was init ially discovered that concentrations of diosgenin dosed cumulatively to the organ chambers did not modify the basal tonus of these rings, both in the absence and on the presence of a functional endothelium. Similar results were collected after administrati on of increasing cumulative doses of 17 - β estradiol diosgenin, which suggests that 17 - β estradiol not seem to modify the basal tonus of superior mesenteric artery isolated of rats. The administration of increasing concentrations of diosgenin or 17 - β estrad iol induced a concentration - dependent relaxation of endothelium, both in the presence and absence of the same, that suggests diosgenin, as well as 17 - β estradiol, have dependent and independent relaxant effect of functional endothelium . The relaxation eff ect mediated by increasing concentrations of diosgenin was significantly potentiated after the thirty minutes incubation with the 17 - β estradiol which suggests that 17 - β estradiol is capable of enhancing the relaxation induced by diosgenin in superior isol ated mesenteric artery of a rat in the presence and absence of the endothelium. However, further studies are required to clarify the action mechanism involved in this enhancement.