Myocardial hypertrophy induced by nephrectomy alters cardiovascular parameters and cardiac GLUT-4 expression in rats

Abstract

Given the discrepancies on the role of glucose in cardiac hypertrophy, the present study was designed to evaluate cardiac Glucose Transporter-4 (GLUT-4) expression during hypertension-induced myocardial hypertrophy, and exercise-induced myocardial hypertrophy in rats.Twenty Wistar rats were divided into four groups of five rats for studies on myocardial hypertrophy induced by unilateral nephrectomy–induced myocardial overload, and exercise-induced hypertrophy. Systolic, diastolic, mean arterial pressure and heart rate were measured along with QRS-interval and R-amplitude. Immunohistochemistry of paraffin embedded myocardial tissues were carried out to estimate the expression of GLUT-4.The systolic, diastolic and mean arterial pressure of unilateral nephrectomy-induced hypertensive rats were significantly increased compared to control. The QRS-interval was significantly prolonged when compared with the control rats. Nephrectomy-induced myocardial hypertrophy caused a significant decrease in the expression of GLUT-4 compared to control. There was no significant difference in blood pressure parameters of exercise-induced cardiac hypertrophy. The QRS interval of the rats subjected to swimming exercise was prolonged significantly but not the R-amplitude. There was no significant difference in the cardiac tissue expression of GLUT-4 exercise-induced hypertrophy rats and control rats.In conclusion, the present study suggest that a decrease in GLUT-4 expression is associated with myocardial hypertrophy arising from unilateral nephrectomy-induced hypertension