Herman Autrup, Human Tissue Studies Section, Experimental Pathology Branch, Division of Cancer Cause and Prevention, NCI, National Institutes of Health, Public Health Service, U.S. Department of Health, Education, and Welfare, Bethesda, Maryland, Denmark
Benjamin F. Trump, United States
James K. Selkirk, United States
Curtis C. Harris, United States
Institute of Environmental and Occupational Medicine
Cultured human bronchial explants activated benzo[alpha]pyrene (BzaP) into electrophilic metabolites that bind to DNA in bronchial epithelial cells. Promutagenic and mutagenic metabolites of BzaP were also released into the culture medium. An increase in mutation frequency for ouabain resistance was found in Chinese hamster V-79 cells when they were cocultivated with bronchial explants in the presence of BzaP. The proximate carcinogenic form of BzaP, the 7,8-diol [(+/-)-r7,t8-dihyroxy-7,8-dihydrobenzo[a]pyrene], was 5-fold more potent as a promutagen than the parent compound. Neither BzaP nor the 7,8-diol increased the mutation frequency in V-79 cells when they were cultured without bronchial explants. The mutation frequency was directly related to the binding levels of BzaP to bronchial DNA and the concentratin of either BzaP or the 7,8-diol in the medium.
Original language
English
Journal
Proceedings of the National Academy of Sciences of the United States of America