The purpose of this study was to clarify the effect of ethanol on restoration of gastric epithelial cells after artificial cell-free area was made in the culture dish. Restoration of such "wounding" was evaluated quantitatively every 12 hr using a computer image analyzer with and without ethanol. Without ethanol, restoration was achieved within 48 hr. Exposure to ethanol retarded cellular restoration significantly. BrdU-positive cells were recognized around the wound from 24 to 36 hr, and then decreased substantially in control. However, BrdU-positive cells were rarely detected in ethanol group. Staining for actin in the control group revealed the presence of lamellipodia and stress fibers. However, the ethanol groups were observed in narrowed lamellipodia and few stress fibers. In conclusion, ethanol retarded the migration and proliferation of cultured gastric mucosal cells after in vitro wounding, possibly by damaging the cytoskeletal system. To evaluate cell mature during restoration of gastric mucosa after ethanol ingestion, the expression of gap junction protein connexin 32 was studied. The injury was most severe 1h after treatment, and was completely resolved by the 4th day after treatment. The number of immunoreactive spots for gap junctions was markedly decreased 1h after treatment. Reappearance of these staining occurred with repair of the injury. The reappearance of connexin 32 was delayed in comparison with both the histological resolution of the injury and the normalization of PAS-stained mucus. The most active cell proliferation stained by BrdU was observed 24h and then normalized 14th day after treatment. These results indicate that morphological repair is different to the recovery of cell maturity and cell proliferation in the regenerative gastric mucosa.