Participation of bivalent ions in the acetylcholine-provoked gastric smooth-muscle phasis contractions.
Experiments were carried out on muscle strips from cat antrum. Acetylcholine added to Ca++ -free medium containing EDTA (10-5M) exerted no effect on the phasic contractions of the gastric smooth muscle. Ba++at low concentrations (0,1 to 0,5mM) replaced Ca++with respect to the acetylcholine effect. On the background of blocked cholinergic (atropine 10-5M) and adrenergic (phentolamine 10-5 M and propranolol 10-5M) structures Ba++ provoked slow potentials and cotractions with a frequency of 9 to 10 cpm. delta600 (10-5M) blocked the Ba++-induced myogenic electrical and contractile activities of the smooth muscle. The role of the cholinergic structures for synchronizing the electrical and contractile activities of the smooth muscle is considered.
D000109:Acetylcholine / Q000494:pharmacology / Q000502:physiology*; D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001464:Barium / Q000494:pharmacology*; D002118:Calcium / Q000494:pharmacology / Q000502:physiology*; D002415:Cats; D004347:Drug Interactions; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology*; D013270:Stomach / Q000187:drug effects
D001464:Barium; D000109:Acetylcholine; D002118:Calcium