Role of the bladder urothelium in voiding dysfunction

Abstract

The urothelium is a highly effective constant permeability barrier that protects the blood from toxic urinary substances. However, a large and growing body of evidence supports additional roles for the urothelium, including sensory and transduction/signaling roles that enable responses to chemical or mechanical stimuli. Reciprocal communication between urothelial cells with closely located bladder nerves and other cell types, including detrusor smooth muscle and interstitial cells, is likely. Diseases affecting the urinary bladder may affect urothelial receptor channel expression and release of chemical mediators. Urothelial neuropeptide receptor, chemokine receptor, and neurotrophin receptor expression, transduction/signaling, and modulation in animal models of urinary bladder inflammation and human studies of bladder dysfunction are presented. Substrates underlying micturition reflex plasticity induced by urinary bladder disease/dysfunction are likely to include bladder primary afferent cells, lumbosacral spinal cord, and the urothelium.