Assessing oxidative stress in Steller sea lions (Eumetopias jubatus): Associations with mercury and selenium concentrations

Lian, Marianne; Castellini, J. Margaret; Kuhn, Thomas; Rea, Lorrie; Bishop, Louise; Keogh, Mandy; Kennedy, Stephanie N.; Fadely, Brian; van Wijngaarden, Edwin; Maniscalco, John M.; O'Hara, Todd

doi:10.1016/j.cbpc.2020.108786

i

Assessing oxidative stress in Steller sea lions (Eumetopias jubatus): Associations with mercury and selenium concentrations

2020
By Lian, Marianne ; Castellini, J. Margaret ; Kuhn, Thomas ; ...

Details

Journal Title:

Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology
Personal Author:

Lian, Marianne ; Castellini, J. Margaret ; Kuhn, Thomas ; Rea, Lorrie ; Bishop, Louise ; Keogh, Mandy ; Kennedy, Stephanie N. ; Fadely, Brian ; van Wijngaarden, Edwin ; Maniscalco, John M. ; O'Hara, Todd
NOAA Program & Office:

NMFS (National Marine Fisheries Service) ; AFSC (Alaska Fisheries Science Center)
Description:

Selenium (Se) bioavailability is required for synthesis and function of essential Se-dependent antioxidants, including the enzyme glutathione peroxidase (GPx). Strong interactions between monomethyl mercury and Se impair the critical antioxidant role of Se. Approximately 20% of Steller sea lion (Eumetopias jubatus, SSL) pups sampled in the western Aleutian Islands, Alaska, had total Hg concentrations ([THg]) measured in hair and whole blood above thresholds of concern for adverse physiologic effects in pinnipeds. Importantly, low molar ratios of TSe:THg, in some cases < 1 in several tissues (hair, liver, pelt, muscle, spleen, intestine, heart, lungs, brain) were documented for one SSL pup with [THg] above threshold of concern, which may lead to antioxidant deficiency. Our aim with this study was to evaluate the relationship between circulating [THg], [MeHg+], [TSe] and TSe:THg molar ratio status relative to oxidative stress and antioxidants measured during general anesthesia in free-ranging SSL. We captured, anesthetized and sampled newborn SSL pups at rookeries located in the Aleutian Islands or Gulf of Alaska. Biomarkers analyzed for oxidative stress included 4-hydroxynenonal and thiobarbituric acid reactive substances (4-HNE and TBARS, respectively, lipid peroxidation), protein carbonyl content (PCC, protein oxidation), and GPx activity as a key indicator for Se-dependent antioxidant defense levels. We found a negative association between TBARS and [TSe], and SSL with low [TSe] had higher concentrations of 4-HNE than those with intermediate [TSe]. These results suggest that SSL with lower [TSe] experience increased lipid peroxidation potentially associated with [THg] status.
Keywords:

Mercury Sea Lions Selenium Sea Lions Glutathione Peroxidase Oxidative Stress Steller Sea Lion
Source:

Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology, 235
DOI:

https://doi.org/10.1016/j.cbpc.2020.108786
Document Type:

Journal Article
Rights Information:

CC BY-NC-ND
Compliance:

Submitted
Main Document Checksum:

urn:sha256:dd9fe85fd6d6428f4dc7a0ec9f791cc46cace36297730798c44ac7cb48e7fc47
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https://repository.library.noaa.gov/view/noaa/28864/noaa_28864_DS1.pdf
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[PDF - 751.04 KB ]

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