The dioxin TCDD protects against aflatoxin-induced mutation in female rats, but not in male rats.
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is an environmental contaminant and a potent carcinogen in laboratory rodents. When combined with other environmental toxins, it has been shown to increase the (geno)toxicity of some compounds. In this study, the effect of TCDD on the mutagenicity of aflatoxin-B1 (AFB1) was examined in the rat liver using a lacI transgenic rodent mutation assay. AFB1 induces GC-->TA transversions. Since TCDD is known to have a differential effect in male and female rodents, both sexes were studied. The data showed that a 6-week pre-exposure to TCDD had no significant effect on the frequency of aflatoxin-induced mutation in the liver of male rats. However, the TCDD treatment completely prevented the aflatoxin-induced transversion mutations in female animals.
Thornton
A S
AS
Centre for Biomedical Research, University of Victoria, Victoria, BC, Canada V8W 3N5.
Oda
Y
Y
Stuart
G R
GR
Holcroft
J
J
de Boer
J G
JG
D016604:Aflatoxin B1 / Q000633:toxicity*; D000818:Animals; D030801:Animals, Genetically Modified; D016587:Antimutagenic Agents / Q000494:pharmacology*; D005260:Female; D008297:Male; D009152:Mutagenicity Tests; D017354:Point Mutation / Q000187:drug effects*; D000072317:Polychlorinated Dibenzodioxins / Q000494:pharmacology*; D051381:Rats; D012737:Sex Factors
D016587:Antimutagenic Agents; D000072317:Polychlorinated Dibenzodioxins; D016604:Aflatoxin B1