Vascular insulin resistance in fructose-hypertensive rats.

Evidence suggests that insulin has direct, potent and physiologically relevant vasodilatory effects. This has led to the hypothesis that in states of insulin resistance, insulin's vasodilatory effects may be blunted leading to an increase in vascular tone and blood pressure. To examine this proposition we studied the direct effects of insulin on the reactivity of aortae from control and insulin-resistant fructose-hypertensive rats to angiotensin II. Insulin incubation caused marked vasodepressor effects in control aortae. Strikingly, this effect was absent in aortae from fructose-hypertensive rats. These data suggest the presence of vascular insulin resistance in fructose-hypertensive rats and provide a hemodynamic basis for hypertension in states of insulin resistance.