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.
Poli
E
E
Institute of Pharmacology, University of Parma, School of Medicine, Italy.
Monica
B
B
Zappia
L
L
Pozzoli
C
C
Bertaccini
G
G
D000328:Adult; D000368:Aged; D004558:Electric Stimulation; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D018727:Muscarinic Antagonists; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D010276:Parasympatholytics / Q000494:pharmacology*; D010277:Parasympathomimetics / Q000494:pharmacology; D010890:Pirenzepine / Q000031:analogs & derivatives* / Q000494:pharmacology; D011976:Receptors, Muscarinic / Q000187:drug effects*; D001743:Urinary Bladder / Q000187:drug effects*
D018727:Muscarinic Antagonists; D010276:Parasympatholytics; D010277:Parasympathomimetics; D011976:Receptors, Muscarinic; C046338:telenzepine; D010890:Pirenzepine