gamma-butyrolactone enhances the activity of GABA in the gastric acid secretion of anesthetized rats.

Influences of gamma-butyrolactone (GBL) on GABA agonists-induced gastric acid secretion were studied in anesthetized rats. GBL potentiated the effect of GABA and GABA agonists on gastric acid secretion, and gamma-hydroxybutyric acid, a metabolite of GBL, tended to enhance the effect of GABA. However, GBL did not influence 2-deoxy-D-glucose- or bethanechol-stimulated acid secretion. A benzodiazepine, diazepam, also increased the secretagogue action of baclofen. A GABA antagonist, bicuculline, but not picrotoxin, inhibited the acid secretion stimulated by the combination of GBL and GABA or muscimol. Aminooxyacetic acid, an inhibitor of GABA transaminase, potentiated the effect of GABA. Dopamine receptor agonists and antagonist did not modify the effect of GABA. Neither GABA mimetic action of GBL nor its influences on the dopaminergic system are involved in the effect of the compound on gastric acid secretion. Although the possibility that GBL inhibits GABA degradation is not excluded, the compound appears to increase the sensitivity of GABA receptor to GABA mimetics in the gastric acid secretion.