Alterations in the vascular renin-angiotensin system in streptozotocin-induced diabetic rats

We have studied changes in the diabetic vascular renin-angiotensin system (RAS) in the model of rat mesenteric artery perfusion. Using purification by highperformance liquid chromatography, we measured the concentrations of aldosterone and AII with a radioimmunoassay method. Aldosterone decreased significantly while there was no significant change in angiotensin II. There was no coherence between vascular aldosterone and AII in the controls (r = -0.081, n = 12, P > 0.05). These results indicate that the main defective step in the vascular RAS of diabetic rats was diminished aldosterone generation. Its actual mechanism is still under investigation. (C) 1998 Chapman & Hall Ltd.