Effect of relaxin on TGF-beta1 expression in cultured vaginal fibroblasts from women with stress urinary incontinence.

The objective of this study is to compare relaxin's effect on transforming growth factor (TGF)- beta1 and latent TGF-beta1-binding protein (LTBP-1) in vaginal fibroblasts from women with stress urinary incontinence (SUI) to continent women (controls) in both phases of the menstrual cycle. Fibroblasts were treated with relaxin. TGF-beta1 levels were measured by enzyme-linked immunosorbent assay. LTBP-1 expression was evaluated by Western blot. In the proliferative phase, total TGF-beta1 level in the supernatant, cells, and extracellular matrix (ECM) of SUI fibroblasts decreased with increasing relaxin concentration (P < .05). Active TGF-beta1 levels increased at a low concentration of relaxin (P < .05) in the supernatant but decreased in the ECM of SUI fibroblasts at high concentration (P < .05). In the secretory phase, total TGF-beta1 levels decreased with relaxin treatment (P < .05) in the supernatant, cells and ECM of both women with SUI and controls. Relaxin decreased the levels of total and active TGF-beta1 in the ECM isolated from SUI vaginal fibroblasts.