EFFECTS OF TESTOSTERONE ON GLOMERULAR GROWTH AFTER UNINEPHRECTOMY

Background. Renal functional prognosis is consistently more adverse in male individuals with renal disease. Male animals develop more marked proteinuria and glomerulosclerosis in several models of renal damage. Renal and glomerular growth are important permissive factors for prog ression of renal failure. Purpose of the study. To investigate the inf luence of testosterone on renal and glomerular growth. Design. Renal c ompensatory growth after uninephrectomy (UNX) was chosen as a model of renal growth. The effect of testosterone was assessed in control male , in orchidectomized (OX) male, and in ovariectomized (OV) female SD r ats. Observation lime was 10 months. Measurements. Albuminuria by neph elometry; glomerular diameter, glomerular tuft area, renal zonal analy sis by quantitative stereology. Testosterone and dihydroxytestosterone by gas chromatography and RIA. Results. In sham-operated male rats, t estosterone administration did not change the (left) kidney:bodyweight ratio after uninephrectomy. In contrast, in OX male rats, testosteron e administration caused a significant increase in kidney:body-weight r atio and in albuminuria. In these animals, glomerular diameter and out er stripe width were significantly lower in OX rats than in sham-opera ted controls. Glomerular volume and outer stripe width in OX animals w ere significantly higher after uninephrectomy (UNX) and were further i ncreased in OX-UNX animals by administration of testosterone. Similar effects on glomerular diameter, cortical width (single) kidney:body-we ight ratio were seen when OV female rats were treated with testosteron e. Conclusion. After gonadal ablation, administration of testosterone amplifies compensatory glomerular and tubular growth in uninephrectomi zed male and female rats, i.e. testosterone is a permissive factor. St imulation of glomerular growth may favour development of glomeruloscle rosis.