SUMMARY Benzo(a)pyrene and five isomenic phenols of benzo (a)pynene were tested for carcinogenicity by the topical application of 0.4 @moIe of each compound to the backs of C57BL/6J mice once every 2 weeks for 60 weeks. 1-, 3-, and 12-hydroxybenzo(a)pyrene were noncarcinogenic , 11-hy droxybenzo(a)pyrene was weakly carcinogenic, and 2-hy droxybenzo(a)pyrene and benzo(a)pyrene were highly car ci...

The metabolism of benzo(a)pyrene has been investigated in cultured normal human bronchus, colon, duodenum, and esophagus obtained from the same patient. The highest total metabolism was found in bronchus and duodenum, while the highest mean binding level was observed in the bronchus followed, in order, by the esophagus, duodenum, and trans verse colon. A 30-fold interindividual variation in the...

Benzo(a)pyrene 4,5-oxide was rapidly reduced to benzo(a)pyrene by rat liver microsomes in the presence of reduced nicotinamide adenine dinucleotide phosphate when incubated anaerobically. The activity of benzo(a)pyrene 4,5oxide reductase was increased about seven times by pretreat ment of rats with 3-methylcholanthrene. The addition of riboflavin to the incubation mixture resulted in the increa...

The potential effect of asbestos fibers on mutagenicity of benzo(a)pyrene was investigated by using the Ames test. Asbestos fibers without a coating of benzo(a)pyrene or benzo(a)pyrene when not dissolved in DMSO lacked any mutagenic effect in the Salmonella/mammalian microsome mutagenicity test. However, when benzo(a)pyrene was adsorbed onto asbestos, significant numbers of mutated bacteria wer...

Benzo(a)pyrene 4,5-oxide was rapidly reduced to benzo(a)pyrene by rat liver microsomes in the presence of reduced nicotinamide adenine dinucleotide phosphate when incubated anaerobically. The activity of benzo(a)pyrene 4,5oxide reductase was increased about seven times by pretreat ment of rats with 3-methylcholanthrene. The addition of riboflavin to the incubation mixture resulted in the increa...

The metabolism of benzo(a)pyrene in cultured human colon has been investigated. Nontumorous colonie tissue was collected at the time of either surgery or "immediate autopsy" from patients with or without colonie cancer. After 24 hr in culture the expiants were exposed to [3H]benzo(a)pyrene for another 24 hr and the binding to cellular DMA and protein was measured. Two adducts, formed between be...