Effects of Captopril and Losartan on Cardiac Stereology in Rats with Renovascular Hypertension

Background: Captopril, an angiotensin-converting enzyme inhibitor, and losartan, an angiotensin II receptor blocker, are used for the treatment of hypertension, but their effects on cardiac stereology are unknown. This study, therefore, aimed to examine their effects on cardiac stereology in rats with renovascular hypertension. Methods: This study was conducted at Histomorphometry and Stereology Research Centre, and Cardiovascular Pharmacology Research Lab, Department of Pharmacology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran, in August 2015 to August 2016. Fourty-eight rats were allocated to six groups (n=8 per each group): a sham group, which received a vehicle (distilled water) and five renal artery-clipped groups, which received the vehicle, captopril (50 or 100 mg/kg/day), or losartan (25 or 50 mg/kg/day). After four weeks, the animals’ systolic blood pressures (mm Hg) were measured, and the total volumes of their heart, myocardium, endocardium, matrix, and myocardial vessels (mm3), as well as the number of their cardiomyocytes, and Purkinje fibers were determined. Data were analyzed using one-way analysis of variance (ANOVA) followed by least significant difference (LSD) test. P value of equal to or less than 0.05 was considered significant.Results: The renal artery-clipped rats receiving the vehicle had a significantly higher systolic blood pressure (p