Effects of Irbesartan on ATPase and Calcineurin in Myocardial Tissue from Renovascular Hypertension Rat
YUAN Ping1,SHANG Qian-hui1,WU Qin2,QIN Yao1,WU Ze-bing1,JIANG Qian-feng1. 1. Institute of Clinical Medine of Zunyi Medical College,Department of Cardiology,Affiliated Hospital of Zunyi Medical College,2. Department of Pharmacology Zunyi Medical College,Zunyi Guizhou 563003,China
Objective To investigate the effects of irbesartan on Na+-K+-ATPase,Ca2+-ATPase and Calcineurin(CaN)in myocardial tissue and cardiac hypertrophy in renovascular hypertensive rats(RHR).Methods The renovascular hypertension was induced by two kidney-one clip method.Twenty-one male Sprague-Dawley rats were randomly divided into three groups:RHR model group(n=7),irbesartan treated group [50 mg/(kg·d)(n=7)],and sham operation group(n=7).Blood pressure was measured before and after operation.The ratio of left ventricular mass and body mass(LVM/BM),and the transverse diameter of myocytes(TDM)of left ventricle(LV)were calculated;the activities of Na+-K+-ATPase,Ca2+-ATPase and CaN of LV were measured by biochemistry and enzymology.Results Compared to the sham operation group,systolic blood pressure(SBP),LVM/BM,TDM,CaN activity in RHR were increased,with concomitanltly decreases in the activities of Na+-K+-ATPase,Ca2+-ATPase.Irbesartan significantly decreased the SBP,LVM/BM,TDM and increased the activities of Na+-K+-ATPase [RHR(6.83±0.80)vs irbesartan(9.53±1.03)μmol Pi/(h·mg pro),P0.01] and Ca2+-ATPase [RHR(6.47±0.77)vs irbesartan(8.06±0.53)μmol Pi/(h·mg pro),P0.01],and inhibited CaN activity [RHR(0.91±0.08)vs irbesartan(0.72±0.05)μmol Pi/(h·mg pro),P0.01].Conclusion Irbesartan reversed left ventricular hypertrophy associated with increases in activities of myocardial Na+-K+-ATPase,Ca2+-ATPase and decreases in CaN activity.