Toxicity of fumonisin B1 to B6C3F1 mice : A 14-day gavage study

Abstract Fumonisin B 1 (FB 1 ) is a fungal toxin produced by members of the genus Fusarium . Ingestion of FB 1 causes species-specific neurotoxic, nephrotoxic, hepatotoxic and pulmonary effects. The clinical, haematological and pathological responses of adult male and female B6C3F 1 mice to FB 1 were assessed following 14 daily gavage doses ranging from 1 to 75 mg FB 1 /kg body weight/day. There were no consistent sex-related changes. Although all responses were modest, the most notable effects of FB 1 were on the liver, bone marrow, adrenals and kidneys. In the liver, hepatocellular single cell necrosis, mitosis and anisokaryosis were observed, accompanied by elevated serum ALT. In the kidneys, minor histopathological changes were confined to female mice, while mild decreases in ion transport and increases in blood urea nitrogen were seen only in males. Small changes in glutathione levels were observed in the kidneys and livers of male mice. Adrenal cortical cell vacuolation was observed at 15 mg FB 1 /kg and higher in females and from 35 mg FB 1 /kg in males. Serum cholesterol was elevated in both male and female mice, possibly due to FB 1 -induced changes in lipid metabolism in the liver and adrenals. Although bone marrow cell numbers were unchanged, increases in vacuolated myeloid cells and lymphocytes were observed in female mice. In general, the degree of changes observed indicate that mice are not as sensitive a model of FB 1 toxicity as rats.