Participation of bivalent ions in the acetylcholine-provoked gastric smooth-muscle phasis contractions
Boev, K.; Papasova, M.
Acta Physiologica et Pharmacologica Bulgarica 2(3): 6-14
1976
ISSN/ISBN: 0323-9950 PMID: 1015320 Document Number: 104783
Experiments were carried out on muscle strips from cat antrum. Acetylcholine added to Ca2+-free medium containing EDTA had no effect on the phasic contractions of the gastric smooth muscle. Ba2+ at low concentrations replaced Ca2+ with respect to the acetylcholine effect. On the background of blocked cholinergic (atropine) and adrenergic (phentolamine and propranolol) structures, Ba2+ provoked slow potentials and contractions with a frequency of 9-10 cpm. D-600 [.alpha.-isopropyl .alpha.-[(N-methyl-N-homoveratryl-.gamma.-aminopropyl]-3,4,5-trimethoxypenylacetonitrile] blocked the Ba2+-induced myogenic electrical and contractile activities of the smooth muscle. The role of the cholinergic structures in synchronizing the electrical and contractile activities of the smooth muscle was considered.