EFFECTS OF ENALAPRIL, LOSARTAN, AND VERAPAMIL ON BLOOD-PRESSURE AND GLUCOSE-METABOLISM IN THE COHEN-ROSENTHAL DIABETIC HYPERTENSIVE RAT

We undertook the present study to examine the effect of the angiotensi n-converting enzyme inhibitor enalapril, the angiotensin II antagonist losartan, and calcium antagonist verapamil on systolic pressure and s pontaneous blood glucose levels in rats from the Cohen-Rosenthal diabe tic hypertensive strain. Genetic hypertension and diabetes developed i n this strain after crossbreeding of Cohen diabetic and spontaneously hypertensive rats. The new rat strain was fed their usual copper-poor sucrose diet, which is essential for the development of this model, an d for 4 weeks received either enalapril, losartan, or verapamil. Systo lic pressure was reduced significantly compared with controls in all t reated groups. Chronic treatment with enalapril or verapamil, but not with losartan, succeeded in lowering spontaneous blood glucose, indica ting improved diabetic control. Data suggest that angiotensin-converti ng enzyme inhibition by enalapril, but not angiotensin II antagonism b y losartan, can improve glucose metabolism in addition to its hypotens ive effect in a genetic diabetic hypertensive rat strain. This confirm s that the drop in glucose with converting enzyme inhibition is highly dependent on bradykinin accumulation. Data further suggest that calci um channel blockade by verapamil can also improve glucose metabolism. The question remains whether the reduction in glucose by verapamil was a result of inhibition of glucogenesis.