Increased expression of transforming growth factor-beta1 during gastric ulcer healing in rats.

This study was done to investigate the expression and localization of transforming growth factor-beta1 (TGF-beta1) in the gastric ulcerated tissues produced by acetic-acid during the healing process, by northern blot analysis and immunohistochemical technique. Ulcerated TGF-beta1 mRNA levels were significantly increased from days 3 to 18, in a similar manner to extracellular matrix proteins, and returned to control levels at the scarred phase. Immunoreactive TGF-beta1 was localized in epithelial cells beneath proliferative zone in intact tissues. In ulcerated tissues, TGF-beta1 was localized in macrophages in the ulcer bed and in fibroblasts or myofibroblasts in the granulation tissues. Treatment with prostaglandin E1 (PGE1) further stimulated ulcerated TGF-beta1 expression, being associated with the acceleration of gastric ulcer healing, while treatment with indomethacin reduced TGF-beta1 expression, being accompanied by the delayed ulcer healing. The combination of PGE1 and indomethacin reversed the indomethacin-induced decrease in ulcerated TGF-beta1. Thus, TGF-beta1 may be implicated in the acceleration of gastric ulcer healing.