Sex and Age Differences in the Distribution of 14C-Sterigmatocystin in Immature and Mature Rats: A Multiple Dose Study

Abstract

Sterigmatocystin, a secondary fungal metabolite, produces a toxic reaction upon administration to experimental animals. Examination of rats that have received multiple doses of ¹⁴C-sterigmatocystin may indicate the response elicited by repeated exposure to foodstuffs containing the mycotoxin. Daily doses of sterigmatocystin, 8 mg/kg equally divided over 13 days, were administered in the feed. Immature rats (50–150 g) and mature rats (200–300 g) of both sexes were studied. On the 14th day, an 8 mg/kg dose of ¹⁴C-sterigmatocystin dissolved in wheat germ oil was orally intubated into the rats. Five rats of each sex and age group were sacrificed at 3, 6, 12, 24, 48, and 96 hours. Biological specimens were collected and analyzed for total radioactivity. Tukey's paired comparison procedure was used to analyze for statistically significant differences in tissue exposure to ¹⁴sterigmatocystin due to age and sex. Statistically significant differences in tissue levels were found in 60% or more of the tissues when comparing mature males vs. immature females and mature males vs. mature females. Age and sex differences were also observed in 45% or less of the tissues in other age or sex comparisons. The sterigmatocystin plasma levels vs. time curves contain multiple peaks that may indicate enterohepatic recirculation. The gradual decline in the log-linear phase resulted in long half-lives, ranging from 61.5 to 130 hours.