Exacerbation of cold restraint-induced gastric ulcer by GABA in mice

AIM: To study the effect of GABA on cold restraint-induced gastric ulcer (CRGU) and its mechanism. METHODS: CRGU was produced in adult male mice at 1 degree C in cold room under restraint for 1 h. The ulcer index indicated the severity of gastric mucosa lesion. Gastric mucin was determined with alcian blue dye. RESULTS: GABA 2 mumol (i.c.v.) accelerated CRGU, Bicuculline (Bic) 0.2 mumol (i.c.v.) did not affect CRGU, whereas Baclofen (Bac) 4 mumol (i.c.v.) exacerbated CRGU. Bic did not modify the exacerbation of CRGU by GABA and Bac. Atropine (Atr) 0.2 mg.kg-1 (s.c.) and Phentolamine (Phen) 2.5 mg.kg-1 inhibited CRGU, and abolished the exacerbation of CRGU by GABA. Cold restraint (CR) decreased the amount of the gastric mucin, but GABA 2 mumol had no effect on CR gastric mucin. CONCLUSION: While GABA-B receptor in brain was activated, exogenous GABA exacerbated CRGU via vagal and sympathetic nerves, bearing no relation to decrease of the gastric mucin or weakening of the gastric mucosal barrier.