Immunomodulation in C57Bl/6 mice following consumption of halogenated aromatic hydrocarbon-contaminated coho salmon (Oncorhynchus kisutch) from Lake Ontario.

This report describes studies designed to assess the immunomodulatory effects associated with the consumption of coho salmon containing halogenated aromatic hydrocarbons (HAHs) and other compounds naturally bioaccumulated from Lake Ontario. Diets containing 33% coho salmon from Lake Ontario or the Pacific Ocean were fed to juvenile C57Bl/6 mice for 2-4 mo. Following 60 d, the mice that consumed Lake Ontario salmon had reduced IgM, IgG, and IgA plaque-forming cell responses to sheep erythrocytes.

Ultrastructure of the liver of Lake Erie coho salmon from post-hatching until spawning.

Hepatocytes were examined in coho salmon, Oncorhynchus kisutch, at several stages in their life cycles, using feral and laboratory-reared fish. Yolksac fry sampled before their first exogenous feed had low glycogen and lipid reserves in the hepatocytes and although 'light' cells were predominant, there was already evidence of a dimorphism in the electron density of hepatocytic cytoplasm. Within 1 day of the first exogenous feeding (a commercial salmonid starter diet) the hepatocytes in the fry contained extensive glycogen pools (up to 50% of the cell volume) and lipid droplets, often contained within the glycogen pools.

Toxic effects in C57B1/6 and DBA/2 mice following consumption of halogenated aromatic hydrocarbon-contaminated Great Lakes coho salmon (Oncorhynchus kisutch Walbaum).

Diets containing coho salmon (Oncorhynchus kisutch Walbaum) from the Pacific Ocean or from Lakes Erie, Michigan, and Ontario [containing a gradation from low to high of halogenated aromatic hydrocarbons, (HAHs)] were fed to C57B1/6 and DBA/2 mice. Following a 4-month dietary exposure to Lake Ontario salmon, both strains of mice demonstrated hepatomegaly. The ethoxyresorufin-O-deethylase (ERR) enzyme levels were elevated in livers of C57B1/6 mice fed diets of salmon from all of the Great Lakes studied, with exceptionally high levels detected in C57B1/6 mice fed Lake Ontario salmon.

Relationship between anaphase aberrations and carcinogenicity in the trout embryo microinjection assay.

An increased incidence of anaphase aberrations was observed in the tissues of rainbow trout embryos (Salmo gairdneri) within 96 hours of exposure to mitomycin [(MM) CAS: 50-07-7; 50 and 100 ng/embryo] and aflatoxin B1 [(AFB1) CAS: 1162-65-8; 13 and 25 ng/embryo] with the use of the trout embryo microinjection assay. High numbers of anaphase aberrations in embryos exposed to MM were associated with low mitotic indices, cell pyknosis, and high embryo mortalities. When the anaphase aberration data for embryos exposed to AFB1 were compared to previously reported carcinogenesis data from the microinjection assay, the incidence of anaphase aberrations in embryos did not show the same quantitative variations as the incidence of hepatic carcinomas in adult trout.

Oil refinery effluents: evidence of cocarcinogenic activity in the trout embryo microinjection assay.

Extracts prepared from oil refinery effluents (soxhlet and XAD-2) were tested for carcinogenic potential by means of the rainbow trout (Salmo gairdneri) embryo-injection bioassay. No neoplasms were detected in fish given injections of refinery extracts alone (with and without exogenous rat S-9 activation). Refinery extracts coinjected with aflatoxin B1 induced elevated frequencies of hepatic neoplasms.