INCREASED EXPRESSION OF TRANSFORMING GROWTH FACTOR-BETA(1) DURING GASTRIC-ULCER HEALING IN RATS

This study was done to investigate the expression arid localization of transforming growth factor-beta(1) (TGF-beta(1)) in the gastric ulcer ated tissues produced by acetic acid during the healing process, by no rthern blot analysis and immunohistochemical technique. Ulcerated TGF- beta(1) mRNA levels were significantly increased from days 3 to 18, in a similar manner to extracellular matrix proteins, and returned to co ntrol levels at the scarred phase. Immunoreactive TGF-beta(1) was loca lized in epithelial cells beneath proliferative zone in intact tissues . In ulcerated tissues, TGF-beta(1) was localized in macrophages in th e ulcer bed and in fibroblasts or myofibroblasts in the granulation ti ssues. Treatment with prostaglandin E(1) (PGE(1)) further stimulated u lcerated TGF-beta(1) expression, being associated with the acceleratio n of gastric ulcer healing, while treatment with indomethacin reduced TGF-beta(1) expression, being accompanied by the delayed ulcer healing . The combination of PGE(1) and indomethacin reversed the indomethacin -induced decrease in ulcerated TGF-beta(1). Thus, TGF-beta(1) may be i mplicated in the acceleration of gastric ulcer healing.