Effects of acetylcholine on the tone and miniature contractions of isolated dog urinary bladder.
Effects of acetylcholine on the tone and miniature contractions of dog urinary bladder were investigated in vitro. In both dome and trigone preparations, cumulative administrations of acetylcholine produced dose-dependent increases in the tone, which were dose-dependently depressed by prior administration of atropine and augmented by neostigmine. The frequency of miniature contractions in the dome and trigone was dose-dependently increased by acetylcholine. The dose-response curves of the frequency for acetylcholine were shifted to the right by atropine and to the left by neostigmine in both preparations. The amplitude of miniature contractions in both preparations was not significantly changed by acetylcholine. A computer analysis showed that changes in the tone of the bladder had the positive correlation to the frequency of miniature contractions. The results indicate that acetylcholine would act on the urinary bladder through activation of muscarinic receptors, and that there is the positive correlation between changes in the tone and the frequency of miniature contractions.
D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005260:Female; D006584:Hexamethonium Compounds / Q000494:pharmacology; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009388:Neostigmine / Q000494:pharmacology; D011976:Receptors, Muscarinic / Q000187:drug effects; D001743:Urinary Bladder / Q000187:drug effects*
D006584:Hexamethonium Compounds; D011976:Receptors, Muscarinic; D009388:Neostigmine; D001285:Atropine; D000109:Acetylcholine