The effect of angiotensin-converting enzyme inhibitors (ACEI) enalapril, lisinopril and ramipril was studied on fructose-induced hypertensive and hyperinsulinaemic rats. 2. 60 Sprague-Dawley rats were fed a fructose-enriched diet for 5 weeks, which produced hyperinsulinaemia, hypertriglyceridaemia and hypertension. Beginning with week 3 of the diet, lisinopril (10 and 20 mg per kg per day), ramipril (5 and 10 mg/kg per day) and enalapril (20 mg/kg per day) were given daily in drinking water for 2 weeks to 10 rats in each drug group. Ten rats fed only the fructose-enriched diet served as control. 3. Systolic blood pressure was measured weekly by the indirect tail-cuff method. Plasma insulin level was determined using RIA. 4. Data indicate that ACEI improve insulin resistance induced by high-fructose intake in rats; that despite their equal hypotensive effect, ACEI differ in their ability to improve insulin resistance; and that improvement of insulin resistance by ACEI is dose-dependent.
