Figure 1.

System for stretching the uroepithelium. Uroepithelial tissue was mounted between two closed Ussing stretch chambers, the chambers were filled with Krebs buffer, and the tissue was equilibrated for 30–45 min. (A) Control tissue was not exposed to mechanical stimuli. (B) Tissue was bowed outward in response to stepwise increases in the hydrostatic pressure head. (C) Hydrostatic pressure was simultaneously raised stepwise in both mucosal and serosal hemichambers. (D) Both the mucosal and serosal hemichambers were maintained at 1 cm H₂O pressure, and the tissue was pulled by a filament toward the serosal hemichamber. (E) Tissue was bowed outward in response to raising hydrostatic pressure in the mucosal hemichamber. (F) Tissue was bowed inward in response to raising hydrostatic pressure in the serosal hemichamber. (G) Tissue was bowed outward as the mucosal hemichamber was filled at different rates. M, mucosal hemichamber; S, serosal hemichamber. The green line between the chambers shows the initial position of uroepithelium and the red curve shows the position of the tissue upon bowing.