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Effects of dietary selenium on tissue concentrations, pathology, oxidative stress, and immune function in common eiders (Somateria mollissima)

Journal of Toxicology and Environmental Health, Part A

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DOI: 10.1080/15287390701212760

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Abstract

Common eiders (Somateria mollissima) were fed added Se (as L-selenomethionine) in concentrations increasing from 10 to 80 ppm in a pilot study (Study 1) or 20 (low exposure) and up to 60 (high exposure) ppm Se in Study 2. Body weights of Study 1 ducks and high-exposure ducks in Study 2 declined rapidly. Mean concentrations of Se in blood reached 32.4 ppm wet weight in Study 1 and 17.5 ppm wet weight in high-exposure birds in Study 2. Mean Se concentrations in liver ranged from 351 (low exposure, Study 2) to 1252 ppm dry weight (Study 1). Oxidative stress was evidenced by Se-associated effects on glutathione metabolism. As Se concentrations in liver increased, Se-dependent glutathione peroxidase activity, glutathione reductase activity, oxidized glutathione levels, and the ratio of hepatic oxidized to reduced glutathione increased. In Study 2, the T-cell-mediated immune response was adversely affected in high-exposure eiders, but ducks in the low-exposure group exhibited evidence of an enhanced antibody-mediated immune response. Gross lesions in high-exposure ducks included emaciation, absence of thymus, and loss of nails from digits. Histologic lesions included severe depletion of lymphoid organs, hepatopathy, and necrosis of feather pulp and feather epithelium. Field studies showed that apparently healthy sea ducks generally have higher levels of Se in liver than healthy fresh-water birds, but lower than concentrations found in our study. Data indicate that common eiders and probably other sea ducks possess a higher threshold, or adverse effect level, for Se in tissues than fresh-water species. However, common eiders developed signs of Se toxicity similar to those seen in fresh-water birds.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Effects of dietary selenium on tissue concentrations, pathology, oxidative stress, and immune function in common eiders (Somateria mollissima)
Series title:
Journal of Toxicology and Environmental Health, Part A
DOI:
10.1080/15287390701212760
Volume
70
Issue:
10
Year Published:
2007
Language:
English
Contributing office(s):
Patuxent Wildlife Research Center
Description:
861-874
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Journal of Toxicology and Environmental Health, Part A
First page:
861
Last page:
874
Number of Pages:
14