PGE2 protects isolated cells against injury through multiple mechanisms.

In order to clarify how PGE2 regulates gastric mucosal integrity, we examined the effects of PGE2 on ethanol-caused injury of isolated gastric chief cells, cultured gastric mucous cells from guinea pigs and Balb/c 3T3 fibroblasts. Pretreatment of these cells with PGE2 reduced ethanol-caused injury of the cells. Furthermore, pretreatment of gastric mucous cells with indomethacin enhanced ethanol-caused injury, suggesting that endogenous PGE2 may be involved in the cell protection. PGE2 stimulated an increase in diacylglycerol (DG) accumulation in chief cells and treatment of chief cells with synthetic DG reduced the injury of the cells. However, DG accumulation was not observed in gastric mucous cells treated with PGE2. Therefore PGE2 may protect the cells from injury through a variety of mechanisms. In addition, PGE2 enhanced the survival of the quiescent fibroblasts cultured in the absence of serum, while PGE2 had no survival enhancing effect on gastric mucous cells. These results suggest that the mechanism by which PGE2 preserves the cell viability may depend on not only cell types used but also how the cells are injured.