Article date: 1990/2/27
PubMed ID: 2155808
Journal name: European journal of pharmacology (ISSN: 0014-2999)
The present study investigates the effects of GABAA- and GABAB-receptor agonists and antagonists on gastric secretion after their i.c.v. administration to conscious pylorus-ligated rats and anaesthetized stomach lumen-perfused rats. Muscimol was without effect in pylorus-ligated rats, whereas baclofen produced a significant decrease in acid secretion, which was fully prevented by phaclofen. Under these conditions, a significant decrease in acid secretion was also obtained with bicuculline. In stomach lumen-perfused rats, muscimol caused a marked, dose-dependent increase in acid secretion, which was antagonized by bicuculline. Under the same conditions, baclofen induced a moderate, but significant, bicuculline-sensitive increase in acid secretion. Overall, our results suggest the presence of two central GABA pathways which mediate opposite effects: (a) a bicuculline-sensitive GABAA-receptor, the stimulation of which increases acid secretion under pharmacological depression of central vagal tone (anaesthetized rats); (b) a phaclofen-sensitive GABAB-receptor, the activation of which decreases vagally stimulated acid secretion (pylorus-ligated rats).
Author List: Del Tacca M, Blandizzi C, Bernardini M C
Publication Types: Journal Article; Research Support, Non-U.S. Gov't
Substances mentioned in the article: Receptors, GABA-A; phaclofen; Muscimol; gamma-Aminobutyric Acid; Baclofen; Bicuculline;
Mesh terms: Anesthesia; Animals; Baclofen/analogs & derivatives; Bicuculline/pharmacology; Central Nervous System/metabolism; Dose-Response Relationship, Drug; Gastric Acid/secretion; Injections, Intraventricular; Male; Muscimol/pharmacology; Pylorus/physiology; Rats; Rats, Inbred Strains; Receptors, GABA-A/metabolism; gamma-Aminobutyric Acid/metabolism;