Influence of prostaglandin on repair of rat stomach damaged by absolute ethanol.

This study was undertaken to determine the possible role that prostaglandins (PGs) may play in enhancing epithelial repair in ethanol-damaged gastric mucosa. Fasted rats were injected subcutaneously with 10 micrograms/kg of 16,16-dimethyl PGE2 or saline and 30 min later received an oral bolus of 1 ml of absolute ethanol or saline. At 5 min and 2, 8, and 24 hr after ethanol exposure tissues were prepared from identical regions of the glandular mucosa for microscopic evaluation. Normal, injured, and repairing tissues were differentiated and quantitated. The length of injured surface epithelium was the same in ethanol-treated tissues with and without PG pretreatment when evaluated 5 min after ethanol exposure, but the deeper epithelium was protected from injury in animals receiving PG pretreatment. Although the repair process itself was identical in the two experimental groups, in PG-treated tissues repair was initiated earlier, was more widespread, and was much more rapid than in tissues exposed to ethanol without such treatment. At the end of 24 hr of observation, only 5.5% of the surface epithelium was considered normal histologically in mucosa exposed to ethanol alone without PG pretreatment. This is in marked contrast to PG-treated tissues in which 82.7% of the gastric surface was normal at 24 hr. The mechanism responsible for our findings is unknown but may be related to PG's ability to spare the cellular pool in the gland isthmus from damage, enhancement of cellular migration from this pool to resurface the damaged epithelium, or a combination of both of these processes.