Diacetoxyscirpenol (DAS, anguidine) was given intravenously to swine at 0.0, 0.5, and 1.0 mg/kg body wt. In mitotically and metabolically active tissues such as gastrointestinal epithelium and lymphoid aggregates the effects of DAS mimicked radiation poisoning. A quadratic dose-response relationship between the cytotoxicity of DAS and damage to enterocytes was found. Enterocytes in different anatomical regions of the bowel had differing susceptibilities to the toxic effects of DAS. In lymphoid tissues, DAS was preferentially cytotoxic to B-lymphocyte-rich tissues as compared to T-lymphocyte-rich tissues. In all pigs dosed with DAS the bone marrow was void of hemopoietic elements. DAS was cytotoxic to cells with specialized ion pumps, namely, renal tubular, gastric parietal, and salivary ducts. Cell damage in the exocrine and endocrine pancreas and adrenal gland accounted for changes in blood glucose. Endothelial necrosis and hemorrhage were observed in the brain. These findings were compared with those reported for other 12,13-epoxytrichothecenes and ionizing radiation and we concluded that a similar mechanism of cytotoxicity could exist.