Central GABAA excitatory and GABAB inhibitory receptors regulate gastric acid secretion in rats

Eur J Pharmacol. 1990 Feb 27;177(3):189-94. doi: 10.1016/0014-2999(90)90269-c.


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).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anesthesia
  • Animals
  • Baclofen / analogs & derivatives
  • Baclofen / pharmacology
  • Bicuculline / pharmacology
  • Central Nervous System / metabolism*
  • Dose-Response Relationship, Drug
  • Gastric Acid / metabolism*
  • Injections, Intraventricular
  • Male
  • Muscimol / pharmacology
  • Pylorus / physiology
  • Rats
  • Rats, Inbred Strains
  • Receptors, GABA-A / metabolism*
  • gamma-Aminobutyric Acid / metabolism*


  • Receptors, GABA-A
  • phaclofen
  • Muscimol
  • gamma-Aminobutyric Acid
  • Baclofen
  • Bicuculline