Immunohistochemical study on the adhesion molecules of the angiogenesis in experimental-gastric ulcer

Angiogenesis of the experimental-gastric ulcer was investigated by means of immunohistochemical staining using monoclonal antibodies (MoAbs) related to adhesion molecules. In order to study the regulation of the antigen-expression defined by REC16-11, REC4-1 and ICAM-1, which recognize varieties of endothelial cells, we assessed their expression on the microvasculature in the granulation tissues using a model of acetic acid-induced gastric ulcer in rats. Microvasculature in the deep layer of granulation tissues were stained by REC16-11 within 5 days of the ulcer development. In contrast, REC4-1 and/or ICAM-1 were detected in microvasculature only from 10 days, in parallel with the degree of LFA-1-positive lymphocytic infiltration around REC4-1-positive-vessels. In cases of healed ulcer on 40 days, the distribution of the positive reaction with those MoAbs was similar to the normal rats. In cases of unhealed ulcers at the same period, REC16-11-positive-vessels were observed in all vascular endothelial cells of the granulation tissues. However, REC4-1 and/or ICAM-1-positive-vessels had the same pattern as the cases on 15 days. The cell adhesion molecules were expressed temporary on the endothelial cells of these microvasculature during the development of granulation tissues after gastric ulcer. Based on these results, it was suggested that the antigens related to adhesion molecules on the endothelial cells may play an important role in the healing process of gastric ulcer.