Inhibitory effects of L-glutamine on the aspirin-induced gastric lesions in the rat

Abstract

The effects of an amino acid, L‐glutamine, on aspirin‐induced gastric lesions and gastric secretion were studied in either intact or pylorus‐ligated rats. L‐Glutamine had a pronounced inhibitory effect on gastric lesions induced by aspirin administered by oral, intraperitoneal, or intraduodenal routes to intact or pylorus‐ligated rats. By the oral route the inhibition was dose‐related. However, L‐glutamine given either intraduodenally or intraperitoneally did not show any appreciable effects on gastric lesions induced by orally administered aspirin in pylorus‐ligated rats. One mechanism of L‐glutamine protection was inhibition of a back diffusion of gastric acid caused by aspirin and this was demonstrated in pylorus‐ligated rats. The reduction in H⁺ and increase in Na⁺ concentrations in the lumen caused by aspirin was returned to normal by increasing doses of L‐glutamine. In addition, L‐glutamine was considered to inhibit the back diffusion of acid caused by pylorus ligation per se, because the amino‐acid produced an increment of H⁺ and reduction of Na⁺ and K⁺ in comparison with the control group. The role of pepsin on L‐glutamine protection was negligible.