Antihypertensive effect of puerarin in renal hypertensive rats and its effect on level of angiotensin II in renal tissue
Zhang Nianbao,Chen Huizhen,Cui Weidong,Ding Boping,Huang Zhenggui (Department of Pharmacology,Wannan Medical College & Pharmacology of TCM Grade Three Laboratory,State Administration of Traditional Chinese Medicine ,Wuhu 241002)
Objective:This experiment was undertaken to observe effects of puerarin on blood pressure and level of angiotension II (ANG II) in renal tissue in two-kidney,one-clip (2K1C) hypertensive rats,and to investigate whether puerarin has an antihypertensive effect and a role in amelioration of renal interstitial fibrosis. Methods:70 Sprague-Dawley rats weighing 180 to 220 grams,half male and half female,were used. Renal hypertensive rat model was established by two-kidney,one-clip. High-,middle-and low-dose puerarin (200 mg/kg,100 mg/kg and 50 mg/kg,respectively) was given intraperitoneally for six weeks. In addition,a sham operation group was set and fed with normal diets. Each group had 8 rats. Blood pressure was measured every two weeks. Rats were sacrificed and kidneys were taken out after 6 weeks of treatment with puerarin. Contents of ANG Ⅱ in renal homogenate were measured by radioimmunoassay. Levels of renal interstitial fibrosis were observed via HE stained kidney slices. Results:High-,middle-and low-dose puerarin decreased blood pressure,and showed a dose-dependent effect (P0.01 or P0.05). Renal interstitial fibrosis was aggravated,which came along with an increase in the level of ANG Ⅱ in renal tissue. High-and middle-dose puerarin reduced levels of ANG II markedly (P0.01 or P0.05),while low-dose puerarin did not change the level of ANG II (P0.05). Puerarin at all three concentrations showed a role in amelioration of renal interstitial fibrosis (P0.01). Conclusion:Puerarin has a dose-dependent antihypertensive effect in renal hypertensive rats. It shows a role in the improvement on renal interstitial fibrosis,and the mechanism may be related to a decrease in level of ANG II in renal tissue and to its antihypertensive effect.