The influence of perindopril on intrarenal RAS in experimental diabetic rats

OBJECTIVE: To examine the effect of perindopril on the intrarenal renin angiotensin system (RAS) in diabetic rats. METHODS: Diabetes of rats was induced by a single injection of STZ. The rats were treated with perindopril (1 mg.kg-1.d-1) and the controls were given insulin only. Plasma and intrarenal renin activity (PRA, TRA) and angiotensin I (PAT I, TATII) were measured by radioimmunoassay in the diabetic rats at 1, 3, 6 months. Message RNA (mRNA) expression of renal angiotensinogen (TATO) and TATII receptor (TATII R) was assessed by slot blot hybridization. RESULTS: At 6 month, TATII levels in the control group were significantly decreased compared with those of normal controls (P < 0.05), and TATII levels in perindopril treated rats were decreased remarkedly compared with those of the control group (P < 0.01). TRA was not different among the three groups at 3 to 6 months (P > 0.05). In slot blot hybridization TATII R mRNA expression in the control group was markedly increased compared with that of perindopril treated and normal control groups (P < 0.05, P < 0.01). TATO mRNA expression was not different among the three groups (P > 0.05) during the experimental period. CONCLUSION: The abnormalities of intrarenal RAS existed in STZ induced diabetic rats, including the decrement of TATII content and the enhancement of TATII R mRNA expression. Perindopril could further decrease the level of intrarenal TATII, and inhibit its receptor mRNA expression.