Abstract
A classic physical barrier, the urothelium has been recognized as a new type of sensory structure. The urothelium can sense bladder distension and transduce the mechanical signal into chemical signal by releasing the sensory mediator ATP. ATP in turn acts on the P2X receptors of the afferent fibers to generate nerve impulses. The suburothelial cell network amplifies the urothelial signal. The system can also respond to a variety of noxious stimuli, contributing to pathological processes. An extensive collection of nociceptive and mechanoreceptive receptors and ion channels enables the urothelium to receive multiple sensory inputs. The pathological importance is evidenced by functional and structural lesions of the urothelium in human bladder pathologies and their experimental models. The distinct ion channel and receptor profiles make the urothelium a promising drug target for more selective pharmacological interventions for the treatment of bladder disorders.