The protective effects of captopril and nitric oxide on solitary kidney after chronic partial ureteric obstruction

Objective To determine whether vasodilator agents (captopril and nitric oxi de) change the morphological and functional effects of chronic partial uret eric obstruction in solitary kidney tissue in unilaterally nephrectomized r ats, Materials and methods Each of 50 prepubertal Wistar albino rats underwent r ight nephrectomy and were then assigned to one of five groups. Rats in grou p 1 underwent a sham operation (control) and in the other groups the ureter of the remaining kidney was partially obstructed by surgery. In group 2, n o drug treatments were given; in groups 3, 4 and 5 captopril, L-arginine me thyl ester (L-Arg) or NG-nitro-L-arginine-methyl ester, respectively, were given for 3 weeks, In all rats, diuretic scintigraphy was used to measure k idney perfusion, glomerular filtration rate (GFR) and concentration. Blood urea nitrogen (BUN), serum creatinine levels, kidney parenchymal weight and pelvic volume were measured and the kidneys evaluated histopathologically. Results Renal perfusion was significantly greater in both group 3 and 4 tha n in group 2, The GFR was 18% greater in group 3 and 22.3% greater in group 4 than in group 2. The GFR was decreased by 67% in group 5 compared with t he control group, The mean parenchymal weight, mean pelvic volume, BUN and serum creatinine in the four groups with a partially obstructed ureter were significantly different from the control group. There also were significan t differences between group 2 and groups 3-5, and between group 2 and group 3. Histological damage was severe in all four groups with partial ureteric obstruction, but in the drug-treated groups, medullary fibrosis was less f requent. Conclusion After 3 weeks of treatment, captopril and L-Arg both improved ki dney perfusion, GFR, BUN and serum creatinine levels, but were less effecti ve in preventing parenchymal atrophy and changes in pelvic volume.