Effect of NG-nitro-L-arginine methyl ester and L-arginine on ethanol-induced gastric mucosal damage in newborn rats

Previous studies have suggested that the mechanisms involved in gastric mucosal protection in newborn rats are different from those in adult rats. The aim of this study was to derermine whether nitric oxide (NO) has protective effects against ethanol-induced gastric mucosal damage in newborn rats. In 1-week-old rats, (1) pretreatment with N-G-nitro-L-arginie methyl ester (L-NAME), a NO synthase inhibitor, increased gastric mucosal damage induced by 35% ethanol dose-dependently (0.3 - 30 mg/kg), (2) concurrent administration of 300 mg/kg L-arginine (L-Arg) inhibited the L-NAME induced-in crease in damage completely, and (3) pretreatment with low dose L-Arg (30 mg/kg) decreased the mucosal damage induced by 60% ethanol. We concluded that endogeneous NO is involuved in the protective mechanism of the gastric mucosa in neonatal rats.