Vasorelaxant Effects of the Isoflavones in Red Clover on Isolated Rat Mesenteric Artery in an Endothelium-dependent Manner / 中国药师

ABSTRACT

Objective:To investigate the vasorelaxant effect of the isoflavones in red clover on rat mesenteric artery rings. Meth-odsThe rat mesenteric artery rings were placed between two L form metal needles. When stable precontractions induced by vasocon-strictor were got, the different concentrations of isoflavones in red clover and ( or) blocker were added to the baths. The isometric ten-sion of the rat mesenteric artery rings was recorded using a myograph system. Results:The isoflavones in red clover could concentra-tion-dependently relax the rat mesenteric artery rings pre-contracted by K+krebs solution (60 mmol·L-1K+), and compared with the control group (Dmso), the difference was statistically significant (P<0. 01). The isoflavones in red clover-induced relaxation was re-duced by the removal of endothelium, and compared with the complete endothelial group, the difference was statistically significant ( P<0. 01). Pretreatment with Nω-nitro-L-arginine-methylesterhydrochloride (L-NAME,10 -4 mol·L-1) could suppress the relaxing re-sponse to the isoflavones in red clover, and compared with the control group, the difference was statistically significant (P<0. 01). However, indomethacin(10 -5 mol·L-1) did not significantly affect the relaxation induced by the isoflavones in red clover (P >0. 05). Conclusion:The vasorelaxant effect of the isoflavones in red clover is through promoting nitric oxide release from vascular en-dothelium.