CASTRATION ATTENUATES PROTEINURIA AND GLOMERULAR INJURY IN UNILATERALLY NEPHRECTOMIZED MALE SPRAGUE-DAWLEY RATS

BACKGROUND: To clarify the pathogenesis of focal and segmental glomeru losclerosis, we investigated the effect of castration on the developme nt of proteinuria and glomerulosclerosis in unilaterally nephrectomize d male Sprague-Dawley (SD) rats. EXPERIMENTAL DESIGN: At 5 weeks of ag e, group 3 was castrated, whereas groups 1 and 2 were sham-operated. A t 6 weeks of age, groups 2 and 3 received unilateral right nephrectomy and group 1 received sham-operation. Body weight, blood pressure, uri nary protein, serum albumin, cholesterol, blood urea nitrogen and seru m creatinine were checked every 2 months from 2 through 12 months afte r right nephrectomy. Control group 1, Nx (nephrectomized) group 2 and castrated (nephrectomized + castrated) group 3 underwent morphologic s tudy 6 months after nephrectomy. In an additional experiment, control group 4, Nx group 5, and castrated group 6 were followed for an additi onal 6 months and used for morphologic study. RESULTS: Growth was sign ificantly stunted in the castrated rats as compared with control and N x rats. Nx rats became proteinuric with age. Castration significantly reduced the proteinuria after 2 months of nephrectomy throughout the e xperiment. The proteinuria in castrated rats tended to decrease as com pared with the controls. The glomerulosclerosis index was significantl y higher in Nx rats than in either the controls or the castrated rats. The three groups showed no significant differences in blood pressure, plasma renin, activity and plasma aldosterone concentration. CONCLUSI ONS: These observations suggest that sex hormones may contribute to th e development of proteinuria and glomerulosclerosis in unilaterally ne phrectomized male SD rats.