Gavage administration of the fungal toxin fumonisin B1 to female Sprague-Dawley rats

The fungal toxin fumonisin B 1 (FB 1 ) is a contaminant of corn-based foods and feeds produced by members of the genus Fusarium. Fumonisin 8, toxicity was examined using gavage administration of purified toxin to female Sprague-Dawley rats. For 11 consecutive days each rat received a single dose of FB 1 at the following concentrations: control (saline), 1, 5, 15, 35, or 75 mg FB 1 /kg body weight/d. Significantly depressed body weight and food consumption occurred at 35 and 75 mg FB 1 /kg/d. 8y the end of the dosing period there were no significant changes in food consumption. Kidneys and bone marrow were most sensitive to FB 1 exposure. Changes in renal morphology were observed from 5 to 75 mg FB 1 /kg/d, accompanied by transient changes in urine osmolality and urine enzyme levels. Increased cellular vacuolation was the primary change associated with bone-marrow toxicity, starting at doses of 5 mg FB 1 /kg/d. Hepatotoxicity was indicated by reduced liver weight, elevated serum alanine amonitransferase (ALT), and mild histopathological changes occurring at doses of 15 mg FB 1 /kg/d and higher. Increased cytoplasmic vacuolation of adrenal cortex cells occurred in rats treated with 15 mg FB 1 /kg/d and higher, indicating that the adrenals are also potential targets of FB 1 . Elevated serum cholesterol, which is a consistent response to FB 1 , was observed at 5 mg FB 1 /kg/d and higher. Based on responses in this study, gavage is an appropriate substitute for longer feeding studies. Compared to previous work with male rats, gender-related differences in FB, responses lacked consistency but indicated that males may be marginally more sensitive than female Sprague-Dawley rats.