Open AccessEffects of Trimebutine Maleate (TM-906) on the Smooth Muscles of Isolated Guinea Pig Gallbladder
Author(s) -
Hideyuki Takenaga,
Tetsuo Magaribuchi,
Hiroyuki Tamaki
Publication year - 1984
Publication title -
japanese journal of pharmacology/japanese journal of pharmacology
Language(s) - English
Resource type - Journals
eISSN - 1347-3506
pISSN - 0021-5198
DOI - 10.1254/jjp.35.439
Subject(s) - acetylcholine , tetrodotoxin , stimulation , contraction (grammar) , chemistry , cholinergic , atropine , methacholine , calcium , endocrinology , medicine , guinea pig , muscle contraction , gallbladder , biophysics , biology , respiratory disease , lung
Effects of trimebutine maleate (TM-906) on the smooth muscles of isolated guinea pig gallbladder were investigated. TM-906 inhibited the contractile responses to cholinergic nerve stimulation (5 Hz) and to acetylcholine (3 X 10(-8) g/ml) to the same extent, both of which produced much the same amplitude of contraction. TM-906 noncompetitively antagonized the contractile response to methacholine, and it caused a parallel shift of dose-response curves for the contractile response to CaCl2 to higher concentrations. Moreover, TM-906 inhibited the contractile response to 50 mM KCl in a dose-dependent manner. On the other hand, TM-906 itself evoked a slight contractile response in a dose-dependent manner. The contractile response induced by TM-906 was prevented by exposure to Ca++-free solution, but not by tetrodotoxin or atropine. From these results, it was suggested that TM-906 inhibited the contractile responses to cholinergic nerve stimulation, acetylcholine, methacholine and 50 mM KCl by reducing the influx of calcium ion across the cell membrane, while it was assumed that TM-906 itself evoked a slight contractile response by increasing in some way the concentration of the intracellular free calcium ion available for the contractile systems.