Tumour initiating activity of dihydrodiols of benzo[b]fluoranthene, benzo[j]fluoranthene, and benzo[k]fluoranthene.
The tumor initiating activities on mouse skin of benzo[b]fluoranthene, (B[b]F), benzo[j]fluoranthene (B[j]F), benzo[k]fluoranthene (B[k]F] and three of their dihydrodiols, 9,10-dihydro-9,10-dihydroxybenzo[b]fluoranthene (B[b]F-9,10-diol), 9,10-dihydro-9,10-dihydroxybenzo[j]fluoranthene (B[j]F-9,10-diol), and 8,9-dihydro-8,9-dihydroxybenzo[k]fluoranthene (B[k]F-8,9-diol) were evaluated. Among the parent hydrocarbons, B[b]F was the most potent tumor initiator, with activity greater than that of B[j]F but less than that of benzo[a]pyrene. B[k]F also showed tumor initiating activity, in contrast to its lack of complete carcinogenic activity on mouse skin. B[b]F-9,10-diol, which can form a bay region dihydrodiol epoxide, was as active as B[b]F. B[j]F-9,10-diol, which would form its dihydrodiol epoxide in a four sided pseudo-bay region, was less active than B[j]F. B[k]F-8,9-diol was inactive. These results, together with parallel metabolic studies, suggest that the formation of bay region dihydrodiol epoxides may not be the major activation mechanism in benzofluoranthene tumorigenesis.
D000818:Animals; D001711:Biotransformation; D002273:Carcinogens / Q000633:toxicity*; D005260:Female; D005449:Fluorenes / Q000378:metabolism / Q000633:toxicity*; D051379:Mice; D008815:Mice, Inbred Strains; D012878:Skin Neoplasms / Q000139:chemically induced*; D013329:Structure-Activity Relationship
D002273:Carcinogens; D005449:Fluorenes; C027704:benzo(j)fluoranthene; C006703:benzo(b)fluoranthene; C022921:benzo(k)fluoranthene