The mutagenic activities toward Salmonella typhimurium TA 100 and tumor initiating activities on mouse skin of the polynuclear aromatic hydrocarbons benzo[k]fluoranthene (BkF), 2-methylBkF, 8-methylBkF, 9-methylBkF and 7,12-dimethylBkF were compared. BkF and 2-methylBkF were the most mutagenic of the compounds tested and had comparable activity; they were more active than 7,12-dimethylBkF. 8-MethylBkF and 9-methylBkF were not mutagenic. BkF and the methylated BkFs had similar tumor initiating activities on mouse skin. The results suggest that 8,9-dihydro-8,9-epoxyBkF might be involved in the metabolic activation of BkF to a mutagen, but do not indicate which metabolite may be involved in BkF tumorigenesis.
Bibliographical noteFunding Information:
This study was supported by National Cancer Institute Grant CA 32242. We thank Mr. Jeffrey Rigotty for his excellent technical assistance.