INDUCTION OF CYCLOOXYGENASE PROTEIN AND STIMULATION OF PROSTAGLANDIN E(2) RELEASE BY EPIDERMAL GROWTH-FACTOR IN CULTURED GUINEA-PIG GASTRICMUCOUS CELLS

The present study was undertaken to investigate whether epidermal grow th factor (EGF) could stimulate prostaglandin E(2) release, and if so, by what mechanism EGF would exert such an effect in gastric mucosal c ells. In cultured guinea pig gastric mucous cells, EGF dose-dependentl y stimulated prostaglandin E(2) release, with maximal stimulation obse rved at 10 ng/ml. EGF stimulated an increase in cyclooxygenase activit y, which was reduced by protein synthesis inhibitor, actinomycin D, an d cycloheximide. EGF also stimulated the enzyme protein synthesis esti mated by Western blot analysis, whereas EGF did not stimulate phosphol ipase A(2) activity. These results suggest that such an effect of EGF on de novo synthesis of cyclooxygenase protein and prostaglandin E(2) release may be involved at least in part in the mechanism of EGF-induc ed local regulation of gastric mucosal integrity.