Homeostasis of gastric mucosa and effects of peptidergic nerve on mucus metabolism

点击翻译按钮获取中文摘要

In this study, we examined the maintenance of gastric mucosa and the role of peptidergic nerve on epithelium.1) Our histochemical findings indicate that immunoreactivity for neuropeptides including CGRP distributes in the nerve fibers of the lamina propria and submucosal layer of rat gastric mucosa. Although CGRP-immunoreactive nerve fibers mainly innervate the submucosal microvasculature, a certain part of these fibers is shown to run parallel and close to the gastric glands in the lamina propria, some of which approach the surface epithelial cells of the rat stomach.2) Radiolabeled mucin was obtained from the tissue of the rat stomachs incubated for 5 h with [3H]glucosamine. The incorporation of [3H]glucosamine into the mucin was stimulated by CGRP in the cultured corpus mucosa.3) Detailed research on the healing process of gastric mucosa from injury due to various necrotizing agents is important for homeostasis of gastric mucosa. To elucidate this issue, we prepared monoclonal antibodies reacting with mucin molecules present in the specific region and layer of the gastrointestinal mucosa. Acetic acid-induced gastric ulcers were prepared in Wistar rats. Following 24-h fasting, the animals were killed at 20, 30 and 50 days after acid insult and their stomachs were removed immediately. A notable but temporary expression of a kind of sialomucin specifically stained with HCM31 was observed in the regenerating epithelia during the healing stage of acetic acid-induced gastric damage.4) These findings suggest that CGRP acts on the corpus surface epithelial cells and participates in the maintenance of the rat gastric mucosa.