EFFECT OF PRAERUPTORUM CAUMARIN ON CARDIAC MASS, MYOCARDIAL ［Ca²⁺］i AND Na⁺, K⁺-ATPase, Ca²⁺, Mg²⁺-ATPase ACTIVITY IN RENOVASCULAR HYPERTENSIVE RATS

AIM To investigate the preventive and reversional effect of praeruptorum caumarin compound on left ventricular hypertrophy in renovascular hypertensive rats (RHR) and its mechanism. METHODS The two-kidney-one-clip (2K1C) RHR model was used. The blood pressure, wet weight of the left ventricle, surface area of myocardial cells, resting ［Ca²⁺］i level and Na⁺, K⁺-ATPase, Ca²⁺, Mg²⁺-ATPase activity of myocardial membrane and mitochondria were measured. RESULTS Praeruptorum caumarin 30 mg·kg^-1·d^-1 was given ig for 9 weeks from the 6th or 9th week after operation in the preventive or regressive group. The blood pressure, left ventricle wet weight and area of myocardial cells of the preventive and regressive group were significantly reduced than that of the LVH group. The resting ［Ca²⁺］i of the both praeruptorum caumarin treated groups (121±13, 133±9 nmol·L^-1) were lower than that of the LVH group (158±7 nmol·L^-1). The KCl-induced ［Ca²⁺］i elevation was decreased more significantly in preventive and regressive group than that of the hypertrophic myocytes. The activity of Na⁺, K⁺-ATPase and Ca²⁺, Mg²⁺-ATPase increased by 40% and 93% in the preventive group, 28.4% and 48.8% in regressive group than that of the LVH group. CONCLUSION Praeruptorum caumarin was shown to prevent and reverse hypertrophy of LVH by lowering ［Ca²⁺］i and inceasing the ATPase activity.