Effects of Great Lakes fish consumption on the immune system of Sprague-Dawley rats investigated during a two-generation reproductive study.
The effects of Great Lakes fish contaminants on several quantitative and functional aspects of the immune system were investigated in the first (F1) and second (F2) generations of Sprague-Dawley rats. The F0 rats were fed either a control diet or diets containing 5 or 20% lyophilized chinook salmon from the Credit River of Lake Ontario (LO) and Owen Sound point of Lake Huron (LH). The F1 and F2 pups were exposed to fish in utero, through the dam's milk to 21 days old, and through the dam's respective diets to 13 weeks of age. The study included an F1-reversibility (F1-R) phase in which rats at 13 weeks of exposure to fish or control diets were switched to the control diet for 3 months. The most outstanding finding was a statistically significant increase in absolute spleen leukocytes and absolute and percentage lymphocytes in the F2 male rats fed the LH fish diets compared to the control and to those fed the LO fish diets with the 20% fish diets having higher cell numbers compared to the LO-5% fish diets. A parallel increase in the T-helper/inducer T-lymphocyte subset numbers was observed. Increased but statistically insignificant plaque-forming cell (PFC) numbers were obtained in the F2 male rats fed the LH fish diets compared to those fed the LO fish diets and in the F1-R female group of rats fed the LH fish diet compared to those fed the LO fish diets. Phagocytosis by resident peritoneal macrophages was significantly increased in the F1 male and F2 female rats fed the fish diets compared to the control. The phagocytic activity was significantly higher in the F2-generation male and female rats fed the LO diets compared to those fed the LH diets. Other parameters including lymphocyte transformation in response to mitogens, the number of Listeria monocytogenes bacteria surviving in the rat spleens, and the natural killer cell activity were not affected significantly by any of the treatments. Overall, the effects of diets containing chinook salmon from the LO and LH sources on the immune system of rats were minimal and were on quantitative rather than on functional aspects of the system. Further focused research would be required in order to establish conclusively that the immune system of cohorts who ingest Great Lakes fish frequently is at a greater risk for adverse effects.
Tryphonas
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Bureau of Chemical Safety, Health Canada, Ottawa, Ontario, K1A 0L2, Canada.
Fournier
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M
Lacroix
F
F
McGuire
P
P
Hayward
S
S
Bryce
F
F
Flipo
D
D
Arnold
D L
DL
D000821:Animal Feed / Q000633:toxicity*; D000818:Animals; D005260:Female; D005506:Food Contamination; D006854:Hydrocortisone / Q000378:metabolism; D007107:Immune System / Q000187:drug effects*; D007694:Killer Cells, Natural / Q000187:drug effects* / Q000502:physiology; D008213:Lymphocyte Activation; D008297:Male; D010587:Phagocytosis / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D012098:Reproduction / Q000187:drug effects*; D012474:Salmon; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D014874:Water Pollutants, Chemical; D006854:Hydrocortisone