Urothelial/Lamina Propria Spontaneous Activity and the Role of M3 Muscarinic Receptors in Mediating Rate Responses to Stretch and Carbachol

The urothelium with the lamina propria exhibits a spontaneous contractile activity that is increased during stretch. The mechanism appears to involve endogenous acetylcholine release acting on M3 muscarinic receptors. Anticholinergic drugs used clinically depress the responses of these tissues, and this mechanism might represent an additional site of action for these drugs in the treatment of bladder overactivity.