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See detailSTUDY OF SELENITE AND SELENOMETHIONINE EFFECT ON METHYLMERCURY IN VITRO TOXICITY
Dupont, Aurélie ULg; Siebert, Ursula; Rosenberger, Tanja et al

Conference (2011, May 16)

Methylmercury (MeHg) and selenium (Se) can be found at elevated concentrations in blood of marine mammals and both display modulatory effects on the immune system. Whereas mercury (Hg)-Se antagonism in ... [more ▼]

Methylmercury (MeHg) and selenium (Se) can be found at elevated concentrations in blood of marine mammals and both display modulatory effects on the immune system. Whereas mercury (Hg)-Se antagonism in liver of marine mammals is well known, the protective role of Se against Hg immunotoxicity in marine mammals has been poorly described. We propose here an in vitro approach using combined Hg and Se in vitro exposure of peripheral blood mononuclear cells (PBMCs) of the harbor seal (Phoca vitulina). PBMCs were isolated from the blood of 10 harbor seals and exposed to environmental concentrations of MeHg (1µM) and selenite or selenomethionine (5µM), respectively inorganic and organic forms of Se. MeHg leaded to a decrease of lymphocyte proliferation, to an increase of cells with compromised mitochondrial membrane potentials and cell death. Preliminary results evidenced that none of the two Se forms had a protective effect against MeHg toxicity, although cells were slightly stimulated by Se alone. Therefore MeHg expresses its toxicity among blood circulating lymphocytes in presence or absence of selenite or selenomethionine. [less ▲]

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See detailMethylmercury and selenium in vitro effects on harbor seal (Phoca vitulina) lymphocytes : a multidisciplinary approach
Dupont, Aurélie ULg; Bouquegneau, Jean-Marie ULg; Das, Krishna ULg et al

Poster (2010, May 26)

Methylmercury (MeHg) bioaccumulates along the food web, leading to the highest levels in tissues of predatory species. It constitutes the predominant form present in the blood of marine mammals. The blood ... [more ▼]

Methylmercury (MeHg) bioaccumulates along the food web, leading to the highest levels in tissues of predatory species. It constitutes the predominant form present in the blood of marine mammals. The blood cells, including the immune cells, are therefore exposed to the toxic properties of that chemical. Nevertheless, selenium (Se) is an essential element absorbed concomitantly to MeHg which seems to modulate this toxicity. The goal of this study is to evaluate the immunotoxicity of MeHg on the harbor seal (Phoca vitulina) T lymphocytes, highly important in the adaptive immune response, and to investigate the modulating effect of Se on that toxicity. In parallel, the concentrations of MeHg, total mercury (T-Hg) and Se are determined in free-ranging harbour seal blood in order to follow their contamination levels. The T lymphocytes were isolated from the whole blood, exposed to various MeHg and Se concentrations and the exposure effects were estimated by functional tests including the evaluation of viability, proliferation, metabolic activity, DNA and protein synthesis, and by morphological analysis by transmission electron microscopy. The mean T-Hg concentration was 172 ± 143 µg/l of whole blood. The T lymphocytes cultures in vitro displayed a decreasing number of viable cells with increasing concentrations of MeHg, and numerous ultrastructural defects. The cells exposed to MeHg notably displayed distortion of the plasmic membrane, nucleus fragmentations, chromatin compaction, swelling mitochondrias and cytoplasmic vacuolisations. Those results highlighted various immunotoxic effects of MeHg, both at the functional and ultrastructural levels. The antagonistic role of Se on MeHg immunotoxicity is discussed. [less ▲]

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See detailMethylmercury in vitro exposure of harbor seal (Phoca vitulina) lymphocytes: a multidisciplinary approach
Dupont, Aurélie ULg; Siebert, Ursula; Rosenberger, Tanja et al

Poster (2009, June 08)

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See detailDevelopment of an in vitro model for mercury exposure in marine mammals
Dupont, Aurélie ULg; Bouquegneau, Jean-Marie ULg; Siebert, Ursula et al

Poster (2007, November 01)

Detailed reference viewed: 16 (6 ULg)