Effect of Nifedipine and Enalapril on Insulin-Induced Glucose Disposal in Spontaneous Hypertensive and Diabetic Rats

Abstract

Hypertension and diabetes mellitus are associated with hyperinsulinemia and insulin resistance. The present work was undertaken to study the effects of enalapril and nifedipine on insulin sensitivity in spontaneously hypertensive (SH) rats and diabetic rats. Insulin sensitivity was measured by insulin tolerance test using K_ITT as an index of insulin mediated glucose metabolism. The time to produce 50% fall in initial blood sugar level (T_1/2) was significantly higher in non-insulin dependent diabetes mellitus (NIDDM) and SH rats as compared to Wistar control. The mean K_ITT values were significantly lower in NIDDM and SH rats as compared to Wistar control. Treatment with nifedipine (10 mg/kg) and enalapril (5 mg/kg) for 15 days produced a significant reduction in T_1/2. Further, K_ITT value was found to be significantly increased in SH rats treated with nifedipine or enalapnl as compared to control. Our data indicate that NIDDM and SH rats are not only hyperinsulinemic but also insulin resistant Nifedipine and enalapril treatment produced increase in insulin sensitivity in these animals.

Key Words:

• Hypertension
• insulin sensitivity
• insulin resistance
• hyperinsulinaemia
• nifedipine
• enalapril