Abstract:

Objective　To investigate the effect of puerarin on the relaxation of mesenteric artery in spontaneously hypertensive rats.　Methods　20 spontaneously hypertensive rats were randomly divided into 5 groups: hypertension group, captopril group, puerarin low, medium and high dose groups, 4 in each group, and 4 WKY as a normal control group. Body weight and blood pressure were measured before administration and 8 weeks after administration，the content of NO in the serum and the content of ET-1 in the plasma were measured，separation of mesenteric tertiary arteries for HE staining , analysis of wall thickness-to-lumen radius ratios(WT/LR) were performed. The relaxation effect of puerarin on endothelium-intact and endothelium-denuded artery rings were measured by pressure myograph. The effect of puerarin on the relaxation of the arterial ring after endothelium-dependent pathway blockers and endothelium-independent pathway blockers after incubation.　Results　The systolic blood pressure difference and diastolic blood pressure difference in the low, medium and high dose groups of puerarin were significantly lower than the hypertension group. Serum NO content decreased and plasma ET-1 levels increased in the high dose group of puerarin. The WT/LR of the mesenteric tertiary arteries in the middle and high dose group of puerarin decreased. Puerarin had a concentration-dependent relaxation effect on endothelium-intact and endothelium-denuded artery rings, but the endothelium-intact arterial ring diastolic effect was stronger. After incubation with endothelium-dependent pathway blockers and endothelium-independent pathway blockers, the relaxation effect of puerarin was significantly attenuated.　Conclusion　The vasodilating effect of puerarin on the mesenteric artery in spontaneously hypertensive rats is both endothelium-dependent and endothelium-independent. The endothelium-dependent pathway is achieved through the NO-sGC-cGMP signaling pathway and is also associated with the promotion of prostatic release. The endothelium-independent pathway of puerarin may be related to the opening of K+ channels on vascular smooth muscle.

Key words: Puerarin;　Mesenteric artery, Vascular structure;　Endothelium-dependent relaxation;　Endothelium-independent relaxation