DIFFUSABLE GROWTH FACTORS INDUCE BLADDER SMOOTH MUSCLE DIFFERENTIATION

Bladder smooth muscle differentiation is dependent on the presence of bladder epithelium. Previously, we have shown that direct contact between the epithelium and bladder mesenchyme (BLM) is necessary for this interaction. In this study, we tested the hypothesis that bladder smooth muscle can be induced via diffusable growth factors. Fourteen-day embryonic rat bladders were separated into bladder mesenchyme (prior to smooth muscle differentiation) and epithelium by enzymatic digestion and microdissection. Six in vitro experiments were performed with either direct cellular contact or no contact (1) 14-d embryonic bladder mesenchyme (BLM) alone (control), (Contact) (2) 14-d embryonic bladders intact (control), (3) 14-d embryonic bladder mesenchyme combined with BPH-1 cells (an epithelial prostate cell line) in direct contact, (4) 14-d embryonic bladder mesenchyme with recombined bladder epithelium (BLE) in direct contact, (No Contact) (5) 14-d embryonic bladder mesenchyme with BPH-1 prostatic epith...