[Effects of perindopril on left ventricular hypertrophy, coronary reserve and mechanical properties of the papillary muscle of the rat with renovascular arterial hypertension]

Abstract

We investigate the effect of a new angiotensin-converting enzyme inhibitor: Perindopril (IRIS) on regression of left ventricular hypertrophy (LVH), coronary blood flow and mechanical performance of isolated papillary muscle in renovascular hypertensive (Goldblatt 2 kidneys-1 clip) Sprague-Dawley male rats. Sham operated rats (G1) and half of hypertensive rats (G2) were studied after 8 weeks. The other half of 8 weeks long hypertensive rats (G3) were treated during 8 weeks with Perindopril in drinking water at a dosage adjusted to maintain blood pressure (BP) measured with tail cuff method under 140 mmHg. The study of each rat included 1) coronary blood flow and resistance measurements under resting conditions and after coronary dilation by carbochrome infusion (9 mg/kg) using left atrial injection of radioactive microspheres (method of Wicker and Tarazi) 2) the study of mechanical performance of the isolated papillary muscle 3) weight of left ventricle after separation of septum and free wall whose subendocardial and subepicardial layers were counted separately. Results (mean +/- SD): (table; see text) MAP: mean pressure. LV/BW: left ventricular mass (mg) per gram of body weight; CR (C): minimal coronary resistance after carbochrome (mmHg/ml/min/100 mg); DL/Dt: peak velocity of shortening at L max preload; Vrelax: peak velocity of relaxation; THR: time of half relaxation; p less than 0.05; p less than 0.01 compared to SHAM. In this model, hypertension induced a 50 p. 100 LVH whose regression was nearly complete after 8 weeks of treatment with Perindopril. Minimal coronary resistance after carbochrome were higher in hypertensive rats compared to sham and return to normal after regression of LVH.(ABSTRACT TRUNCATED AT 250 WORDS)