Open AccessEffects of GABA antagonists and structural GABA analogues on baclofen stimulated gastric acid secretion in the rat.
Author(s) -
Nobuyuki Hara,
Youichi Hara,
Yoshiaki Gotō
Publication year - 1990
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.52.345
Subject(s) - baclofen , bicuculline , gabab receptor , gabaa receptor , secretagogue , chemistry , pharmacology , antagonist , gastric acid , gaba receptor antagonist , medicine , endocrinology , receptor , secretion , biochemistry , biology , agonist
The effects of GABA receptor antagonists (bicuculline and phaclofen) and structural GABA-analogues on baclofen stimulated gastric acid secretion were studied in standardized perfused rat stomach preparations. Pretreatment with bicuculline, a GABAA-receptor antagonist, in the doses of 1 and 3 mg/kg, subcutaneously, had no influence on the gastric acid response to baclofen. In addition, phaclofen, a GABAB antagonist, in the doses of 3 to 30 mg/kg, intravenously, was found to have no significant effect on the acid response to baclofen. However, GABA-analogues (MOPS and ABA; 10-30 mg/kg, i.v.) and lipophilic GABA derivatives structurally related to beta-amino acids (APPA and APHA; 30 mg/kg, i.v.) significantly counteracted the secretagogue action of baclofen. Further experiments on APPA action showed that the antisecretory effect of APPA could be overcome by higher doses of baclofen. APPA did not affect bethanechol stimulated acid secretion. These results suggest that the secretagogue action of baclofen is independent to GABAA- and GABAB-receptors and that APPA may interact with baclofen in regulation mechanisms of acid secretion, although further investigations are necessary to define the mode of action of APPA on the GABA-ergic system.