Geographic distribution of selected elements in the livers of polar bears from Greenland, Canada and the United States

Rush, Scott A.; Borgå, Katrine; Dietz, Runé; Born, Erik W.; Sonne, Christian; Evans, Thomas J.; Muir, Derek C.G.; Letcher, Robert J.; Norstrom, Ross J.; Fisk, Aaron T.

doi:10.1016/j.envpol.2007.09.006

Cited by 44 publications

(50 citation statements)

References 34 publications

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“…McDowell et al (1995) found that average Se concentration in the liver of white-tailed red deer was 0.676 μg/g d.w. Millán et al (2008) reported that the liver selenium concentration in red foxes and badgers from Spain averaged 1.72 and 4.88 μg/g d.w., respectively Statistical analysis showed that young animals up to 1 year of age were characterized by significantly (P≤0.01) lower concentration of selenium in the liver compared to older animals. A similar relationship in other animal species was observed by Rush et al (2008) and Conover and Vest (2009). We believe that such a low concentration of Se in young wild boars could result from more rapid metabolism in these animals.…”

Section: Discussionsupporting

confidence: 77%

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Liver and kidney concentrations of selenium in wild boars (Sus scrofa) from northwestern Poland

et al. 2010

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The aim of this study was to determine liver and kidney concentrations of selenium in wild boars from the northwest part of Poland, depending on season of the year, age, sex, and body weight. Altogether, samples of livers and kidneys from 172 wild boars that were shot in 2005-2008 were investigated. Liver and kidney concentrations of selenium were determined using spectrofluorometric method. In all the animals studied, selenium concentration was several times lower in the liver than in the kidneys. Selenium concentration averaged 0.19 μg/g wet weight (w.w.) in the liver and 1.20 μg/g w.w. in kidneys. The present study showed that season (P≤0.05), age (P≤0.01), and body weight (P≤ 0.01) have a significant effect on selenium concentration in the liver of wild boars. Liver selenium concentration was the highest in spring (0.23 μg/g w.w.) and the lowest in autumn (0.16 μg/g w.w). Young animals (up to 1 year of age) and those with the lowest body weight (up to 20 kg) were characterized by a slightly lower selenium concentration in the liver compared to older and heavier animals. No significant differences were found in organ selenium concentration between males and females. According to biochemical criteria for the diagnosis of selenium deficiency in pig liver, which were used to evaluate selenium concentration in the liver of wild boars, no individuals were found to have optimal levels. Considering that in Se deficiency higher selenium concentrations are found in kidneys than in the liver, it can be presumed that the wild boars had Se deficiency. However, this is difficult to state conclusively because there are no reference values for this species.

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Section: Discussionsupporting

confidence: 77%

“…No correlation between Se concentration and sex was also reported by Nicpoń et al (2005) in dogs, Conover and Vest (2009) in eared grebes (Podiceps nigricollis), and Rush et al (2008) in polar bears. Meanwhile, Millán et al (2008) found that the liver of female red foxes and mongooses had higher Se concentrations compared to the males.…”

Section: Discussionsupporting

confidence: 70%

Liver and kidney concentrations of selenium in wild boars (Sus scrofa) from northwestern Poland

et al. 2010

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“…However, it should be noted that much higher liver Hg concentrations were reported about 25 years ago in apparently healthy polar bears (e.g., Norstrom et al, 1986). Compared to liver Hg data from 2002 (Rush et al, 2008) and early 1980s (Norstrom et al, 1986), Routti et al (2011) recently reported that in bears sampled in 2005-2008 from Alaskan, Canadian and East Greenland subpopulations, Hg in liver appeared to have increased only in East Greenland bears. Nevertheless, additional research is warranted to better characterize sublethal toxic effects of Hg accumulation in organs other than the brain in polar bears and other Arctic marine mammals.…”

Section: Methylmercury Toxicity In Other Organsmentioning

confidence: 88%

Recent progress on our understanding of the biological effects of mercury in fish and wildlife in the Canadian Arctic

Scheuhammer

Braune

Chan³

et al. 2015

Science of The Total Environment

193

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This review summarizes our current state of knowledge regarding the potential biological effects of mercury (Hg) exposure on fish and wildlife in the Canadian Arctic. Although Hg in most freshwater fish from northern Canada was not sufficiently elevated to be of concern, a few lakes in the Northwest Territories and Nunavut contained fish of certain species (e.g. northern pike, Arctic char) whose muscle Hg concentrations exceeded an estimated threshold range (0.5-1.0 μg g(-1) wet weight) within which adverse biological effects begin to occur. Marine fish species generally had substantially lower Hg concentrations than freshwater fish; but the Greenland shark, a long-lived predatory species, had mean muscle Hg concentrations exceeding the threshold range for possible effects on health or reproduction. An examination of recent egg Hg concentrations for marine birds from the Canadian Arctic indicated that mean Hg concentration in ivory gulls from Seymour Island fell within the threshold range associated with adverse effects on reproduction in birds. Mercury concentrations in brain tissue of beluga whales and polar bears were generally lower than levels associated with neurotoxicity in mammals, but were sometimes high enough to cause subtle neurochemical changes that can precede overt neurotoxicity. Harbour seals from western Hudson Bay had elevated mean liver Hg concentrations along with comparatively high muscle Hg concentrations indicating potential health effects from methylmercury (MeHg) exposure on this subpopulation. Because current information is generally insufficient to determine with confidence whether Hg exposure is impacting the health of specific fish or wildlife populations in the Canadian Arctic, biological effects studies should comprise a major focus of future Hg research in the Canadian Arctic. Additionally, studies on cellular interactions between Hg and selenium (Se) are required to better account for potential protective effects of Se on Hg toxicity, especially in large predatory Arctic fish, birds, and mammals.

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“…The lack of a relationship between Se concentration and sex was also observed in other animal species such as dogs [26], wild boars [27] and polar bears [28]. On the other hand, Millán et al [29] found statistically significant differences in selenium concentrations between male and female red foxes and mongooses.…”

Section: Hepatic Selenium Concentrationsmentioning

confidence: 88%

Glutathione Peroxidase (GSHPx) Activity in the Liver of Red Deer in Relation to Hepatic Selenium Concentrations, Sex, Body Weight and Season of the Year

Pilarczyk

Drozd

Pilarczyk

et al. 2011

Biol Trace Elem Res

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The purpose of this study was to determine glutathione peroxidase (GSHPx) activity in the liver of red deer in relation to selenium concentrations in the liver, as well as to evaluate changes in GSHPx activity according to sex, body weight and season of the year. Total selenium concentration in the liver of red deer averaged 0.095 ± 0.018 μg/g of wet weight. GSHPx activity in the liver of red deer ranged widely from 4.4 to 45.8 U/g of protein. Females were characterized by higher GSHPx activity compared to males (21.2 vs. 17.0 U/g protein). The highest GSHPx activity was recorded in autumn and the lowest in summer. The lowest GSHPx activity in the liver was found in the heaviest animals (>100 kg body weight), averaging 14.0 U/g protein. Animals weighing <66 kg and 66-100 kg were characterized by similar activity of 25.1 and 24.5 U/g, respectively. Despite the differences in GSHPx activity according to sex, body weight and season of the year, these factors had no significant effect on the activity of this enzyme. The main factor regulating GSHPx activity in the liver of examined red deer was selenium concentration.

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Geographic distribution of selected elements in the livers of polar bears from Greenland, Canada and the United States

Cited by 44 publications

References 34 publications

Liver and kidney concentrations of selenium in wild boars (Sus scrofa) from northwestern Poland

Liver and kidney concentrations of selenium in wild boars (Sus scrofa) from northwestern Poland

Recent progress on our understanding of the biological effects of mercury in fish and wildlife in the Canadian Arctic

Glutathione Peroxidase (GSHPx) Activity in the Liver of Red Deer in Relation to Hepatic Selenium Concentrations, Sex, Body Weight and Season of the Year

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