REGENERATION OF GASTRIC MUCOSAL DEFECT

Especially Differentiation of Pseudopyloric Gland

Abstract

We have previously reported that foveolar epithelium and pseudopyloric gland regenerated from the bases of gastric glands, when the defected area was composed by stripping the upper side of gastric mucosa.
The present study attempted to investigate the further differentiation of those regenerated foveolar epithelium and pseudopyloric gland in rats.
"Erosive areas" which consisted of the bases of glands were made by stripping the 2/3 zone of upper side of gastric mucosa at the anterior wall of fundic area, near antral stomach. Surrounding mucosa of the erosive area was completely removed, thus annular ulcer of Ul-II stage was made close to antral stomach. Then the erosive area was surrounded with squamous epithelium spreading from antral stomach and showed the appearance like an "island". The "island" which consisted of the bases of fundic glands was observed for a long period.
Foveolar epithelium and pseudopyloric gland regenerated from differentiated cells in the bases of glands 3 weeks after and this pseudopyloric gland increased gradually 5 weeks after. Then pseudopyloric gland transformed into parietal cells and unmatured chief cells and decreased in number 6 to 8 weeks after. Chief cells and parietal cells increased gradually and well differentiated fundic glands regenerated 10 to 15 weeks after. Besides, chief cells and parietal cells were derived from the proliferative cells in the deep part of foveolar epithelium during the period. However, pseudopyloric gland spreading under the squamous epithelium did not differentiate and remained unchanged throughout the period.
As a conclusion, pseudopyloric gland which appeared in the injured mucosa of fundic area had the capacity to differentiate into chief cells and parietal cells and to regenerate gastric fundic gland. The role of pseudopyloric gland was considered to differentiate into chief cells and parietal cells, appearing in the injured region promptly.