The effect of enalapril on the renal resistive index measurements, urine electrolytes and renal TGF ß-1 levels in a rat model of unilateral ureteropelvic obstruction

Ureteropelvic (UP) junction obstruction is the most common cause of childhood hydronephrosis. The aim of this study is to investigate renal arterial resistive index (ARI) measurements and urine electrolytes before and after enalapril therapy in a rat model of unilateral ureteropelvic obstruction. Also, TGF-ß1 response of the renal tissue in obstructed kidney, main mediator of tubulointertitial fibrosis, and the effects of enalapril therapy on this response is investigated.Thirty Wistar-albino rats were randomly allocated into five groups (n=6). Only laparatomy was performed in the sham (S) group. The treatment (E) group was only treated with 200 mg/kg/day dose of enalapril for 2 weeks orally. The UP obstruction (UP) group and UP obstruction and treatment (UPE) group were both subjected to left unilateral moderate partial obstruction. Two weeks after establishing partial UP obstruction, UPE group was treated with the same dose of enalapril for 2 weeks. In all groups 24 hours? urine was collected. Intrarenal ARI measurements were performed before operation and before and after enalapril treatment in group UPE, and before and after enalapril treatment in group E. Rats were sacrificed by intracardiac puncture and left kidneys were harvested in order to evaluate the levels of mRNA TGF-ß1.In conclusion, enalapril maintained renal blood flow by decreasing ARI and renal tubular functions by protecting urine concentration and dilution ability in a unilateral ureteropelvic obstructed rat model. There was no difference in renal mRNA TGF-ß1 levels. Also, ARI was a reliable indicator in determining the presence of unilateral partial ureteropelvic obstruction.