Urine levels of active and latent/total TGF-β1 at baseline and after CYP. Active and latent/total TGF-β1 values are reported as pg/mg of creatinine. Panel A - Urine levels of TGF-β1 at baseline. In the absence of CYP injection, male and female rats excreted very low amounts of TGF-β1. Total (empty black triangle) and active (solid black triangle) forms of TGF-β1 in male urine were significantly higher than total (empty black dot) and active (solid black dot) forms in female urine p < 0.001 (n = 8). The TGF-β1 levels in male urine were at least 10-fold higher than levels in female urine. Panel B - Urine levels of TGF-β-1 after CYP. Injection of CYP induced time dependent 100-fold increase in urine levels of TGF-β1 in rats of both sexes relative to the respective baseline values. TGF-β1 levels after CYP were significantly higher than respective baseline values only in male urine and not in female urine (ANOVA, Tukey's post hoc test; p < 0.01). The levels of total TGF-β1 (empty black triangle) in male urine after CYP were also significantly higher than the levels of active (solid black dot) and total (empty black dot) TGF-β1 in female urine both at baseline and after CYP (ANOVA, Tukey post hoc test; p < 0.01). The urine levels of total TGF-β1 (empty black triangle) were significantly higher than those of active TGF-β1 (solid black triangle) only in male urine and not in female urine after CYP (*p < 0.01).