ANTIMUSCARINIC ACTIVITY OF TELENZEPINE ON ISOLATED HUMAN URINARY-BLADDER - NO ROLE FOR M1-MUSCARINIC RECEPTORS

1. The antimuscarinic activity of the selective M1-blocking drug, telenzepine, was investigated on the isolated human urinary bladder, contracted with exogenous muscarinic agonists and with field stimulation 2. Telenzepine (3 x 10(-8)-10(-5)M) concentration-dependently shifted to the right the dose-response curves of bethanechol, acetylcholine and McN-A343, and partially depressed the electrically-evoked twitch responses. 3. pA2 values of telenzepine against bethanechol and McN-A343 were very close. 4. McN-A343 did not modify twitch responses elicited by field stimulation up to 10(-5)M. 5. The lack of muscarinic M1 receptors in human detrusor muscle is confirmed