The progression of adriamycin-induced nephrotic syndrome in rats and the effect of captopril.

The progression of adriamycin-induced nephrotic syndrome in rats was studied over a 3-month period. The effect of an angiotensin-converting enzyme inhibitor, captopril, on this model of renal disease, was also studied. Two weeks following a single iv injection of adriamycin, rats were divided into two treatment groups: one received a daily po dose of captopril and the other received a placebo. Measurements of renal function were performed at 4, 8, and 11 weeks following the initiation of therapy. Necropsies and light microscopic evaluation of the kidneys were performed at the end of the treatment period. Functional and morphologic alterations in both groups of rats were compared to each other and to normal age/weight-matched control rats studied over the same time period. At 13 weeks following the administration of adriamycin, both treatment groups had significant renal dysfunction when compared to normal controls. In addition to severe proteinuria, rats receiving adriamycin exhibited polyuria, polydipsia, increased plasma urea nitrogen and plasma creatinine, and decreased endogenous creatinine clearance. They had severe generalized kidney lesions characterized by tubular dilation and atrophy, cast formation, interstitial fibrosis and lymphocytic infiltration, and focal, global glomerulosclerosis. The histopathologic ranking of the kidneys was correlated with some antemortem laboratory parameters but not with the degree of proteinuria. Captopril had no ameliorating effects on the progression of renal disease. Certain findings indicate that captopril may actually have promoted the deterioration of renal function. We conclude that adriamycin-induced nephrotic syndrome in the rat is a progressive disease resulting in generalized renal dysfunction, and that captopril, at the dose given in this experiment, is unable to slow the progression of the disease.