S phase cells of regenerative epithelium in the healing process of gastric ulcer determined by an in vitro BrdU-anti BrdU method

In order to investigate the healing process of gastric ulcer, cell proliferation kinetics of the regenerative mucosa over gastric ulcers was studied by an in vitro bromodeoxyuridine (BrdU)-anti BrdU method. In addition, the effect of histamine H2 receptor antagonists on gastric cell kinetics was also studied. The BrdU labeling index (L.I.) at the site ulcer margin, which were determined by the ratio of labeled cells to epithelial cells of gastric mucosa, were significantly higher in cases of endoscopic A to S1 stage ulcer than in cases of the atrophic gastritis served as control. While the mean L.I. of surrounding mucosa, approximately 1 cm apart from the ulcer margin, in the stage A to S1 were also significantly higher than that of control, the value in the stage S2 was almost comparable to the value of control. There were no differences of L.I. between the cases treated with and without H2 receptor antagonists. These results suggest that in the healing process of ulcer not only reserved epithelial cells at the ulcer margin but also the cells apart from the margin participate in mucosal regeneration. And it seems advisable to consider the stage S2 rather than the stage S1 as the most precise healing stage of ulcer. H2 receptor antagonist may not give an influence on proliferative properties of regenerating mucosal epithelium.