We tested the hypothesis that recognized gastroprotective agents exert direct protection against ethanol-induced injury in isolated rat gastric mucosal cells in vitro. If protection exists, we also wanted to identify subcellular targets in the reversible and/or irreversible stages of cell injury. Ethanol-induced cell injury was quantified by measuring plasma membrane leakage (trypan blue exclusion and lactate dehydrogenase release), mitochondrial integrity (succinic dehydrogenase), and nuclear damage (ethidium bromide-DNA fluorescence). Initial cell viability and responsiveness were estimated by the effects of carbachol, carbachol + atropine, or 16,16-dimethyl-PGE(2) on chief cell pepsinogen secretion. Enriched parietal cells were stimulated by histamine, carbachol, or histamine + IBMX. Preincubation of cells with PG, sucrose octasulfate, or the sulfhydryl compounds N-acetylcysteine, taurine, or cysteamine increased cell resistance