Vascular albumin permeability and hypertrophy in a rat model combining streptozotocin-induced diabetes and genetic hypertension.

OBJECTIVE

To investigate the effects of hypertension and diabetes mellitus on vascular albumin permeability and hypertrophy in 11-week-old Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR) with and without 3 weeks of streptozotocin-induced diabetes.

METHODS

Vascular albumin permeability was measured as tissue content of intravenously injected Evans blue dye.

RESULTS

Diabetic rats showed hypertrophy of the kidneys, and hypertensive rats showed hypertrophy of the heart. In the mesenteric artery there was an additive hypertrophic effect of diabetes and hypertension. The Evans blue content in kidneys was higher in diabetic SHR than in diabetic and in control WKY rats. The kidney: plasma Evans blue ratio was higher in diabetic SHR than in the other three groups, and the heart: plasma Evans blue ratio was higher in diabetic SHR than in control WKY rats or control SHR. The Evans blue content and tissue: plasma Evans blue ratio did not differ in aorta, mesenteric artery or skeletal muscle among the groups. There was no positive correlation between vascular albumin permeability and hypertrophy in any of the tissues studied.

CONCLUSIONS

There was no relationship between vascular albumin permeability and hypertrophy, but increased vascular albumin permeability was found in kidneys and hearts of rats with both diabetes and hypertension. This suggests an additive or synergistic effect of diabetes and hypertension in producing vascular changes.