[Protective effect of prostaglandin E2 on ethanol-induced injury of chief cells isolated from guinea pig].

The mechanism by which PGE2 directly protects individual gastric cells from ethanol-induced injury was studied by using isolated gastric chief cells from guinea pig. Ethanol dose-dependently caused chief cell injury which was estimated by the release of lactate dehydrogenase (LDH) from chief cells. Pretreatment of chief cells with PGE2 reduced the cell damage caused by ethanol in time- and dose-dependent manner. The pretreatment at 37 degrees C and pH 7.4 with PGE2 maximally reduced the cell damage. This protective effect was reduced when the pretreatment was performed at either acid or alkaline pH or at reduced temperature. PGE2 did not stimulate any increase in cytosolic free Ca2+ concentration and initial Ca2+ influx rate. On the other hand, PGE2 stimulated an increase of cAMP accumulation in chief cells. However, pretreatment of chief cells with secretion, VIP, dbcAMP or forskolin failed to reduce subsequent injury caused by ethanol. These results suggest that PGE2 may protect chief cells against ethanol-caused injury probably via PGE type receptors coupled to as yet unidentified signal in gastric chief cells.