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).
|Autori:||Del Tacca M.; BLANDIZZI C; Bernardini M.C.|
|Titolo:||Central GABA-A excitatory and GABA-B inhibitory receptors regulate gastric acid secretion in rats|
|Anno del prodotto:||1990|
|Digital Object Identifier (DOI):||10.1016/0014-2999(90)90269-C|
|Appare nelle tipologie:||1.1 Articolo in rivista|