title: Potentiating effect of Bay K 8644 on agonist-induced ileal contractions.
abstract: The effects of Bay K 8644 on agonist-induced ileal contractions were investigated. Histamine, serotonin and a acetylcholine (10(-8)-10(-4) M) produced a dose-dependent contraction. Maximum contraction was obtained by 10(-5) M serotonin. Its value was 1076 mg. Bay K 8644 (10(-6) M) increased the potency of histamine and serotonin-induced ileal contractions, but acetylcholine induced responses were not increased. All responses of agonists were inhibited by nifedipine (10(-6) M). This inhibition was decreased with increasing acetylcholine concentrations. These results suggest that histamine and serotonin induced/mediated contractions in guinea-pig ileum are independent of calcium influx through voltage operated channels.
authors.affiliation: Department of Pharmacology and Toxicology, Faculty of Medicine, Karadeniz Technical University, Trabzon, Turkey.
authors.forename: N M
authors.initials: NM
authors.lastname: Gacar
authors.forename: N I
authors.initials: NI
authors.lastname: Kalyoncu
authors.forename: Z
authors.initials: Z
authors.lastname: Aksoy
authors.forename: N
authors.initials: N
authors.lastname: Sivrikaya
authors.forename: O
authors.initials: O
authors.lastname: Ugurbas
authors.forename: A H
authors.initials: AH
authors.lastname: Mollaoglu
authors.forename: M
authors.initials: M
authors.lastname: Caglar
mesh_terms: D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology*; D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D015220:Calcium Channels / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D005260:Female; D006168:Guinea Pigs; D006632:Histamine / Q000494:pharmacology; D007082:Ileum / Q000187:drug effects* / Q000502:physiology; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D009543:Nifedipine / Q000494:pharmacology; D012701:Serotonin / Q000494:pharmacology
chemical_list: D015220:Calcium Channels; D012701:Serotonin; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D006632:Histamine; D009543:Nifedipine; D000109:Acetylcholine