Urinary bladder mucosal responses to ischemia.

Abstract

The objectives of this study were to examine the expression of various cellular proteins within the urothelium (UT) and lamina propria (LP) following chronic bladder ischemia in the rat urinary bladder. Urinary bladders were removed from adult Sprague-Dawley rats 8weeks after creation of bladder ischemia and from sham controls. Immunocytochemistry was used to examine distribution of LP-vimentin-immunoreactive (IR) cells and connexins (Cx26; Cx43), and western immunoblotting or ELISA for proteins involved in UT barrier and sensory functions. Ischemia was associated with a significant increase in LP-vimentin-IR cells and increased expression of the gap junction proteins Cx26 and Cx43 within the bladder UT as compared to sham control. Ischemia also resulted in an increased (p<0.05) expression level of the junctional marker (ZO-1) and non-significantly increased expressions of the trophic factor nerve growth factor as well as norepinephrine. Our findings reveal that chronic ischemia alters a number of proteins within the UT and underlying LP. These proteins are involved in barrier function, remodeling, repair as well as intercellular communication. The increased expression of LP-vimentin-IR cells suggests that changes in cell-cell interactions could play a role in ischemia-induced changes in bladder activity.