Histopathological changes in the duodenum of MT-KO mice 1.5 hours after gastric administration of ethanol. A, isocaloric maltose water; B, zinc; C, ethanol; D, zinc and ethanol. Ethanol treatment caused massive degeneration of duodenal villi and hemorrhage. Zinc pretreatment inhibited these morphological anomalies. Hematoxylin and eosin staining; magnification, × 260.