EFFECT OF AN INSULIN SENSITIZER, PIOGLITAZONE, ON HYPERTENSION IN FRUCTOSE-DRINKING RATS

To determine whether insulin resistance is responsible for the develop ment of hypertension, we examined whether blood pressure changes in an insulin-resistant animal that was given a fructose solution as their drinking water. Wistar Kyoto rats that drank a 10% fructose solution f or 10 weeks showed significant increases not only in plasma triglyceri de and insulin levels but also in systolic blood pressure. The decreas e in blood glucose in response to the intraperitoneal injection of ins ulin (0.2-1.0 U/kg) was slight in these fructose-drinking rats. To con firm whether insulin resistance contributes to the observed hypertensi on, we examined the effect of pioglitazone, an insulin sensitizer, on blood pressure in rats given a 10% fructose solution. When pioglitazon e was administered to the rats at a dose of 10 mg/kg/day for 4 weeks f rom 12 weeks of age, plasma triglyceride and insulin levels and systol ic blood pressure decreased, and blood glucose reduction in response t o insulin was normalized. These results suggest that insulin resistanc e is responsible for the development of hypertension in fructose-drink ing rats.