Potentiating effect of Bay K 8644 on agonist-induced ileal contractions

• Published in: Polish journal of pharmacology Vol. 45; no. 4; p. 413
• Main Authors: Gacar, N M, Kalyoncu, N I, Aksoy, Z, Sivrikaya, N, Ugurbas, O, Mollaoglu, A H, Caglar, M
• Format: Journal Article
• Language: English
• Published: Poland 01-07-1993
• Subjects: 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester - pharmacology; Acetylcholine - pharmacology; Animals; Calcium Channels - drug effects; Calcium Channels - metabolism; Dose-Response Relationship, Drug; Drug Interactions; Female; Guinea Pigs; Histamine - pharmacology; Ileum - drug effects; Ileum - physiology; In Vitro Techniques; Male; Muscle Contraction - drug effects; Muscle, Smooth - drug effects; Nifedipine - pharmacology; Serotonin - pharmacology
• ISSN: 1230-6002

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.