The dual effect of BAY K 8644 on excitation-contraction coupling in gastric smooth muscle.
1. BAY K 8644 at concentrations of 10(-10)-10(-6) M had a stimulant effect on the spontaneous electrical and contractile activity of smooth muscle preparations from cat and guinea pig stomach. 2. Nifedipine (10(-6) M) antagonized the BAY K 8644-induced spike potentials and the related phasic contractions. 3. Neither the excitatory nor the inhibitory effect of BAY K 8644 was significantly influenced by atropine (10(-7) M), phentolamine (10(-7) M), propranolol (10(-7) M) or TTX (10(-6) M). 4. TEA (10(-3) M) abolished the inhibitory effect of BAY K 8644 on the spike generation and increased the amplitude of the phasic contractions.
Milusheva
E
E
Institute of Physiology, Bulgarian Academy of Sciences, Sofia.
Boev
K
K
Papasova
M
M
D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002415:Cats; D004594:Electrophysiology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D009543:Nifedipine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D013270:Stomach / Q000187:drug effects*; D013757:Tetraethylammonium Compounds / Q000494:pharmacology; D013779:Tetrodotoxin / Q000494:pharmacology
D013757:Tetraethylammonium Compounds; D013779:Tetrodotoxin; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D001285:Atropine; D011433:Propranolol; D009543:Nifedipine