Castration attenuates proteinuria and glomerular injury in unilaterally nephrectomized male Sprague-Dawley rats

To clarify the pathogenesis of focal and segmental glomerulosclerosis, we investigated the effect of castration on the development of proteinuria and glomerulosclerosis in unilaterally nephrectomized male Sprague-Dawley (SD) rats.

At 5 weeks of age, group 3 was castrated, whereas groups 1 and 2 were sham-operated. At 6 weeks of age, groups 2 and 3 received unilateral right nephrectomy and group 1 received sham-operation. Body weight, blood pressure, urinary protein, serum albumin, cholesterol, blood urea nitrogen and serum creatinine were checked every 2 months from 2 through 12 months after right nephrectomy. Control group 1, Nx (nephrectomized) group 2 and castrated (nephrectomized + castrated) group 3 underwent morphologic study 6 months after nephrectomy. In an additional experiment, control group 4, Nx group 5, and castrated group 6 were followed for an additional 6 months and used for morphologic study.

Growth was significantly stunted in the castrated rats as compared with control and Nx rats. Nx rats became proteinuric with age. Castration significantly reduced the proteinuria after 2 months of nephrectomy throughout the experiment. The proteinuria in castrated rats tended to decrease as compared with the controls. The glomerulosclerosis index was significantly 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.

These observations suggest that sex hormones may contribute to the development of proteinuria and glomerulosclerosis in unilaterally nephrectomized male SD rats.