EFFECT OF ACUTE AND CHRONIC LOSARTAN TREATMENT ON GLUCOSE-TOLERANCE AND INSULIN SENSITIVITY IN FRUCTOSE-FED RATS

The purpose of this study was to evaluate the role of angiotensin II ( AII) in fructose-treated rats by assessing the effects of acute and ch ronic losartan treatment on glucose tolerance and insulin sensitivity. The effect of acute losartan treatment was assessed on blood glucose and serum insulin profiles during an intravenous glucose tolerance tes t (IVGTT) in control and fructose-fed rats. Acute losartan treatment w as effective in lowering both blood glucose and plasma insulin profile s in fructose-treated rats during the IVGTT compared to the saline-inj ected fructose-treated rats. In a subsequent study, 2 weeks after chro nic fructose and losartan treatment, IVGTT were performed. Chronic los artan treatment also improved both the glucose tolerance and insulin s ensitivity in fructose-treated rats. Additionally chronic losartan tre atment also was effective in blocking the hyperinsulinemia, hypertensi on, and cardiac hypertrophy observed in fructose-fed rats. In neither acute nor chronic studies were there any effects of losartan in contro l animals. These results strongly suggest that the renin-angiotensin s ystem modulates the insulin resistance, hypertension, and cardiac hype rtrophy in fructose-treated rats.