Effect of Captopril on Renal Function during Exercise in a Patient with Unilateral Renal Agenesis

The frequent incidence of focal glomerular sclerosis (FGS) in solitary kidneys has attracted a great deal of attention in recent years [1, 2]. It is supposed that glomerular hyperfiltration is mainly related to the development and progress of FGS [3]. We would like to report on the changes of renal function and urinary albumin excretion during exercise and the effect of captopril on those functions in a patient with unilateral renal agenesis. Case Report A 21-year-old man was referred to our hospital for evaluation of orthostatic proteinuria from which he had suffered since the age of 18. Unilateral (right) renal agenesis was revealed by intravenous pyelography and computed tomography. Surgical renal biopsy revealed glomerular hypertrophy, although focal and segmental glomerular sclerotic lesions were not seen in 54 glomeruli including juxtamedullary glomeruli. After admission we examined two factors: (1) the changes in renal function and urinary albumin excretion during exercise, and (2) the influence of captopril (50 mg peroral dosage) on the above-mentioned functions. Urinary albumin excretion during moderate exercise remarkably increased to 161.2 ng/min, and the filtration fraction (FF) during moderate exercise also increased to 0.35. Captopril was particularly effective in decreasing urinary albumin excretion during moderate exercise to 30.2 ng/min accompanied by a decrease in the FF to 0.21 (table I).