Micropuncture measurements revealed that approximately 9 to 10 months after uninephrectomy and maintenance on a high-protein diet, glomerular capillary BP was significantly higher in male than in virgin female rats. This might account for the greater susceptibility of the male to age- and ablation-induced glomerular damage reported by others, although at the time of the present studies, significant reduction in function and worsening in glomerulosclerosis in males v females was barely evident. In a second group of chronically uninephrectomized females, the effects of multiple (five) consecutive pregnancies and lactations were investigated and did not indicate any severe deleterious long-term effects of pregnancy on the glomeruli in this model of underlying renal compromise. Variable responses to an acute intravenous glycine challenge which did not correlate well with the extent of glomerular damage were observed in each group, suggesting that this test may not always be informative regarding underlying glomerular disease.