Repair of gastric ulcer

Summary

By a cryosurgical method a mucosal defect was produced in the body of the rat stomach, and repair of the gastric ulcer was studied with ³H-thymidine autoradiography. From 18 to 24 hours after cryoinjury, cell proliferation in the fundic mucosa was much increased, as indicated by an increase in the labeling index of the cells in the proliferating cell zone of the mucosa, or by reactive incorporation of ³H-thymidine into the mucous neck, chief and parietal cells. Spatially, the increased cell proliferation was found in a region of the mucosa more than 600 μrn distant from the injury, and lasted for more than 14 days. The mucous neck and chief cells around the ulcer which had incorporated ³H-thymidine seemed to transform into flat cells after mitotic division and then continued to divide. After 3–5 days, so called regenerating epithelium or covering epithelium appeared around the ulcer. The upper part of this regenerating epithelium consists of tall columnar cells, the lower part is composed of cystic glandular structures, in which many ³H-thymidine incorporating cells were seen. The formation of new glands in the mucosal defect appeared to take place by budding from these cystic glandular structures with subsequent differentiation of surface epithelial cells. After 3 weeks the mucosal defect was covered by mucinous glandular structures similar to the proper pyloric mucosa. The proliferating cells were confined to the middle level in the regenerated mucosa.