RAPID REPAIR OF THE SURFACE EPITHELIUM IN HUMAN GASTRIC-MUCOSA AFTER ACUTE SUPERFICIAL INJURY

Morphologic changes associated with rapid epithelial repair in human g astric mucosa were examined by light and transmission electron microsc opy in samples obtained at biopsy. A timed series of samples covering six intervals (3-30 min) after exposure to 50% (vol/vol) ethanol was a vailable. Samples exposed to 25% ethanol and to acidified sodium tauro cholate were also studied. Changes indicative of epithelial repair wer e first seen in samples fixed 15 min after ethanol. In samples fixed 3 0 and 45 min after exposure to barrier breakers, there were widespread changes indicative of epithelial repair. We have tentatively identifi ed three morphologically distinct types of repair: lateral movement of the epithelial cell basal plasma membrane, which maintains close cont act with the basal lamina and which may occur only in the presence of continued vascular perfusion; migration of shortened, cuboidal cells w ith blunt pseudopods and lamellipodia. This morphology predominated ov er sites of vascular congestion; and the formation of epithelial arche s in which the epithelial cells did not make contact with the underlyi ng basal lamina. Rapid repair by cell migration was observed only at s ites in which a grossly intact basal lamina was present.