The role of gastric mucosal hexosamine in aspirin-induced ulcers

In order to elucidate the role of gastric tissue hexosamine, used as an index of mucopolysaccharide content, in the development and healing process of peptic ulcers, the distribution of hexosamine and the changes of gastric hexosamine content in the development and healing of aspirin-induced ulcers in rats were studied. In addition, the effects of proglumide and L-glutamine on gastric hexosamine were also studied. The hexosamine content was found to be the highest in the antrum, followed by the corpus and then the forestomach. The mucosa contained significantly higher hexosamine than the smooth muscle layer in both the antrum and the corpus. Prior treatment with proglumide significantly increased the mucosal hexosamine to the extent of 10.3--18.1% in the glandular stomach. Administration of aspirin decreased the gastric mucosal hexosamine and induced the onset of ulcer, while administration of proglumide suppressed the gastric lesions in proportion to dosage and correspondingly prevented a decrease of the hexosamine. In contrast, L-glutamine showed an anti-ulcerogenic effect without suppressing a decrease of the hexosamine. In the process of curing gastric lesions, proglumide accelerated the healing of the ulcers and simultaneously returned the total hexosamine content to its original level. These results suggest that the gastric mucosal hexosamine is closely related to the onset and healing of aspirin-induced ulcer in rats, and that proglumide contributes to both the prevention and healing of ulcers by increasing gastric mucosal hexosamine.