Effect of spironolactone on the development of nephrotic range proteinuria. The age at onset of nephrotic range proteinuria was compared between treatment groups. At the 36-week time point, 70.8% of the control mice had nephrotic proteinuria (as opposed to 51.3% and 48.6% of the mice treated with 25 mg/kg per day and 50 mg/kg per day, respectively). Sixteen animals were included in each group at the start of the study. P = 0.331, control versus spironolactone 50 mg/kg per day.