Effect of dose on the inhibition of carcinogenesis/mutagenesis by aroclor 1254 in rainbow trout fed aflatoxin B/sub 1/

Journal Article · Sun Jan 01 04:00:00 EST 1984 · J. Toxicol. Environ. Health; (United States)

DOI:https://doi.org/10.1080/15287398409530529· OSTI ID:5971416

Shelton, D W; Hendricks, J D; Coulombe, R A; Bailey, G S

Prior studies have shown that Aroclor 1254 (PCB) differentially alters the incidence of aflatoxin B/sub 1/ (AFB/sub 1/) induced hepatocellular carcinomas in trout, depending upon the time of PCB administration relative to AFB/sub 1/ exposure. When fed simultaneously with AFB/sub 1/, PCB inhibits carcinoma incidence. The effect of AFB/sub 1/ and PCB dose on this inhibition was investigated. Duplicate tanks of 100 rainbow trout were fed AFB/sub 1/ at concentrations of 1, 4, or 8 ppb, either with or without the addition of 50 ppm PCB. Other groups were fed 4 ppb AFB/sub 1/ + 5 ppm PCB, 50 ppm PCB alone, or control diet alone. After 9 and 12 mo, 40 and 60 fish per tank, respectively, were sampled to determine the incidence of liver tumors. The results show a parallel inhibition of the AFB/sub 1/-tumor dose-response curve by the presence of 50 ppm PCB. Fish fed 4 ppb AFB/sub 1/ + 5 ppm PCB showed slight inhibition in response when compared with 4 ppb AFB/sub 1/ alone. Also, livers from fish fed 50 ppm PCB were used to prepare S20 for use in the Salmonella mutagenesis assay. These livers were less efficient in converting AFB/sub 1/ to a mutagen, when compared to control S20. The AFB/sub 1/-mutagenesis dose-response curve was again shifted parallel to the right of the curve generated using control S20. These results suggest that the inhibitory action is at least partly at the level of carcinogen activation. The finding of parallel, as opposed to proportional, inhibition with varying carcinogen exposure for certain classes of inhibitors may have important implications for inhibition of environmental carcinogenesis at low levels of carcinogen exposure. 26 references, 1 figure, 3 tables.

• Research Organization: Oregon State Univ., Corvallis
• OSTI ID: 5971416
• Journal Information: J. Toxicol. Environ. Health; (United States), Journal Name: J. Toxicol. Environ. Health; (United States) Vol. 13:4-6; ISSN JTEHD
• Country of Publication: United States
• Language: English

Related Subjects

560305* -- Chemicals Metabolism & Toxicology-- Vertebrates-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AFLATOXIN
ANIMALS
ANTIGENS
AQUATIC ORGANISMS
AROMATICS
BIOLOGICAL EFFECTS
BODY
CARCINOGENESIS
CARCINOMAS
CHLORINATED AROMATIC HYDROCARBONS
DATA
DIGESTIVE SYSTEM
DISEASE INCIDENCE
DISEASES
DOSE-RESPONSE RELATIONSHIPS
EXPERIMENTAL DATA
FISHES
GLANDS
HALOGENATED AROMATIC HYDROCARBONS
INFORMATION
INGESTION
INHIBITION
INTAKE
LIVER
MATERIALS
METABOLIC ACTIVATION
MUTAGENESIS
NEOPLASMS
NUMERICAL DATA
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANS
PATHOGENESIS
TOXIC MATERIALS
TOXINS
TROUT
VERTEBRATES