Effect of continuous infusion of GABA and baclofen on gastric secretion in anaesthetised rats

Continuous infusion of gamma- aminobutyric acid (GABA) and baclofen (BAC) on gastric acid and pepsin secretion in perfused rat stomach showed that GABA (25-100 mg/kg/hr, i.v.) and BAC (1 mg/kg/hr, i.v.) increased the acid output which was blocked by bicuculline (Bicc, 1 mg/kg, i.v.) when given 30 min before their infusion. However, lower dose of GABA (5 mg/kg/hr) and hig her doses of BAC (5 or 10 mg/kg/hr) did not show any significant effect on acid secretion. GABA (5 and 25 mg/kg/hr) inhibited peptic output and again Bicc in the above dose inhibited the inhibitory effect of 25 mg/kg/hr of GABA on peptic output. The result indicate dichotomy on the effects of GABA on acid and pepsin secretion. As both the effects were blocked by Bicc, involvement of GABAA receptor may be a possibility. The antiulcer effect of GABA and BAC could not be due to their effect on gastric acid secretion, but may be due to inhibition of pepsin secretion by GABA or effects of GABA or BAC on mucosal defensive factors.