Carcinogen adducts as an indicator for the public health risks of consuming carcinogen-exposed fish and shellfish.
A large variety of environmental carcinogens are metabolically activated to electrophilic metabolites that can bind to nucleic acids and protein, forming covalent adducts. The formation of DNA-carcinogen adducts is thought to be a necessary step in the action of most carcinogens. Recently, a variety of new fluorescence, immunochemical, and radioactive-postlabeling procedures have been developed that allow the sensitive measurement of DNA-carcinogen adducts in organisms exposed to environmental carcinogens. In some cases, similar procedures have been developed for protein-carcinogen adducts. In an organism with active metabolic systems for a given carcinogen, adducts are generally much longer lived than the carcinogens that formed them. Thus, the detection of DNA- or protein-carcinogen adducts in aquatic foodstuffs can act as an indicator of prior carcinogen exposure. The presence of DNA adducts would, in addition, suggest a mutagenic/carcinogenic risk to the aquatic organism itself. Vertebrate fish are characterized by high levels of carcinogen metabolism, low body burdens of carcinogen, the formation of carcinogen-macromolecule adducts, and the occurrence of pollution-related tumors. Shellfish, on the other hand, have low levels of carcinogen metabolism, high body burdens of carcinogen, and have little or no evidence of carcinogen-macromolecule adducts or tumors. The consumption of carcinogen adducts in aquatic foodstuffs is unlikely to represent a human health hazard. There are no metabolic pathways by which protein-carcinogen or DNA-carcinogen adducts could reform carcinogens. Incorporation via salvage pathways of preformed nucleoside-carcinogen adducts from foodstuffs into newly synthesized human DNA is theoretically possible.(ABSTRACT TRUNCATED AT 250 WORDS)
Dunn
B P
BP
British Columbia Cancer Research Center, Vancouver, Canada.
D000818:Animals; D002274:Carcinogens, Environmental / Q000009:adverse effects* / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D005399:Fishes / Q000378:metabolism*; D005506:Food Contamination / Q000032:analysis*; D011083:Polycyclic Compounds / Q000378:metabolism / Q000633:toxicity; D011634:Public Health; D012307:Risk Factors; D012758:Shellfish / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000009:adverse effects* / Q000378:metabolism
D002274:Carcinogens, Environmental; D011083:Polycyclic Compounds; D014874:Water Pollutants, Chemical; D004247:DNA