ABSTRACT
AIM:Toinvestigatetheeffectofrhynchophylline(Rhy)onbloodpressure,cardiachypertrophy and myocardial fibrosis in spontaneously hypertensive rats ( SHR) .METHODS:Spontaneously hypertensive rats were ran-domly divided into model group , high dose (10 mg? kg-1? d-1 ) and low dose (2.5 mg? kg-1? d-1 ) group of rhyncho-phylline, captopril group (17.5 mg? kg -1? d-1).Wistar-Kyoto rats were used as normal control.Respectively, systolic blood pressure was measured by tail cuff every 2 weeks.After 10 weeks, heart weight index and left ventricular weight in-dex were calculated .The myocardial hydroxyproline and plasma angiotensin Ⅱwere detected .Moreover , basic myocardial histopathological changes and myocardial collagen fibres were observed by HE staining and Masson staining , respectively . The protein expression of TGF-β1 and Smad3 in the myocardium was measured by the methods of immunohistochemistry and Western blot .RESULTS:Compared with SHR model group , Rhy significantly reduced blood pressure ( P<0.05 ) , the levels of HYP in the myocardium (P<0.05) and the levels of AngⅡin the plasma (P<0.01).The pathological dama-ges of the myocardial tissues and collagen deposition were attenuated .The protein expression of TGF-β1 and Smad3 was sig-nificantly reduced by the treatment with Rhy (P<0.01).CONCLUSION:Rhynchophylline reduces blood pressure and adjusts to improve ventricular remodeling of SHR .The mechanism may be involved in the TGF-β1/Smad pathway and re-ducing AngⅡcontent.