Morphological aspects produced by isoproterenol-induced enalaprilat in the myocardium, diaphragm and gastrocnemius muscle of rats

Abstract

Objective: To evaluate the mechanism of enalaprilat, an angiotensinconvertingenzyme inhibitor, as a promoter of hypertrophy reversionin different types of myocytes, left ventricular hypertrophy is animportant physiological predictive factor that helps preventing heartdiseases, because its inducing mechanism is associated to bodymass index, hypertension, hypercholesterolemia, smoking, diabetesmellitus and use of medication. These mechanisms are employedin indexes to assess risks. Methods: Left ventricle, diaphragm andgastrocnemius muscle of 80 male Wistar rats were divided into fivedistinct groups: control, isoproterenol, enalaprilat, isoproterenolenalaprilatgroup and isoproterenol-water. The heart, diaphragm andgastrocnemius muscles were submitted to histomorphometry ofmyocytes under light microscopy analysis. Results: The wet weight– dry weight ratio was increased in the control and isoproterenolgroups. Histomorphometric analysis showed ventricular hypertrophy inrats treated with isoproterenol. In addition, no significant statistical ormorphological differences were observed among the other experimentalgroups. Conclusion: There is strong evidence that left ventricularhypertrophy can be stimulated primarily by neurohumoral activatoragents and stretching mechanisms related to the sympathetic nervousand renin-angiotensin-aldosterone systems. Enalaprilat increases thehypertrophy regression in the left ventricle, but not in the diaphragmand the gastrocnemius muscles.

Keywords

• Hypertrophy
• left ventricular/chemically induced
• Isoproterenol
• Enalaprilat
• Diaphragm/drug effects
• Gastrocnemius muscle/drug effects
• Myocytes
• cardiac/drug effects