Bladder tissue levels of TGF-β-1 in control and CYP-treated rats. Bladder lysate from different groups were analyzed for TGF-β1 by ELISA, and levels of TGF-β1 were then standardized by bladder weight and expressed as μg per bladder. Male rats exhibited the highest expression of TGF-β1 in tissue compared to tissue levels of other groups (ANOVA, Tukey's Multiple post hoc test; *p < 0.05). Levels of active TGF-β1 (Panel A) in bladder tissue were nearly 100-fold higher than levels of latent TGF-β1 (Panel B) measured in bladder tissue of all groups. The substantial presence of latent TGF-β1 in female rats at baseline (open bars) and after CYP (shaded bars) was accompanied by only a minor presence of active TGF-β1 (0 - 3.6 ng; Panel C). In contrast, male rats exhibited both active and latent TGF-β1 at baseline and after CYP, with positive Pearson's coefficients of 0.65 and 0.75, respectively but without statistical significance (p = 0.24).