Effects And Vascular Related Mechanisms Of Paeonol On Renal Hypertension Rats

Paeonol(Pae)is the main active monomer of Cortex Moutan,and has significant anti-arrhythmia,anti-atherosclerosis,anti-ischemia /reperfusion injury,anti-hepatic fibrosis,anti-ischemic neuro-degene-ration and other extensive pharmacological activities.Renovascular hypertension is one of the most common secondary hypertension,which can cause functional and organic damage to multiple organs and systems such as heart,brain and blood vessels.Developing antihypertensive drugs with precise targets has always been the focus of related disciplines.Nitric oxide(NO)is an important humoral factor involved in the long-term regulation of arterial blood pressure.NO in cardiovascular system is mainly synthesized and released by vascular endothelial cells under the catalysis of endothelial nitric oxide synthase(eNOS).In this study,two kidneys and one clip renal hypertension rat model was used to observe the changes of blood pressure by intragastric administration of Pae.The effects and molecular mechanism of Pae on isolated aortic rings were observed by in vitro perfusion and molecular biology techniques.Objective: To observe the effects of Pae on arterial blood pressure and to investigate the effects of Pue on thoracic aorta vasodilatation and the possible mechanisms in renal hypertension rats.Methods: Male adult Sprague-Dawley(SD)rats were randomly divided into four groups.Sham operation group(Sham),sham operation + paeonol group(Sham + Pae),renal vascular hypertension group(RVH),renal vascular hypertension + paeonol group(RVH + Pae).Renal hypertension model was made by two kidney one clip method.The changes of arterial blood pressure were observed by non-invasive tail arterial pressure measurement.The vasodilatation of thoracic aorta was recorded by using organ bath technique and PowerLab biological function experiment system.The levels of eNOS protein expression were determined by using Western blot.Results:1.Intragastric administration of Pae significantly decreased the mean arterial blood pressure(MAP)of RVH rats at 1h,2h,4h,8h after administration(P<0.05).After 6 days of continuous treatment of Pae,the MAP of RVH rats decreased to normal levels.2.Pae could induce the vasodilatation of thoracic aorta in rats dose-dependently(P < 0.05).The effects on RVH was more significant than that of Sham groups(P < 0.05).de-endothelium or pretreatment with L-NAME could ablished the vasodilation effects of Pae.3.Pae increased the expression of eNOS in thoracic aorta tissue(P < 0.05).The effects on RVH groups were more significant than that of Sham rats(P < 0.05).Conclusions: Pae significantly decreased the MAP of RVH rats.This effect of Pae is related to the activation of eNOS expression in endothelial cells and the induction of vasodilation.