title: Absence of selenium protection against methylmercury toxicity in harbour seal leucocytes in vitro.
abstract: Previous studies described high concentrations of mercury (Hg) and selenium (Se) in the blood of harbour seals, Phoca vitulina from the North Sea. In the present study, we evaluated the in vitro potential protective effects of sodium selenite (Na2SeO3) and selenomethionine (SeMet) on cell proliferation of harbour seal lymphocytes exposed to MeHgCl 0.75μM. In vitro exposure of ConA-stimulated T lymphocytes resulted in severe inhibition of DNA synthesis, likely linked to severe loss of mitochondrial membrane potential at 0.75μM. Neither selenite nor SeMet showed a protective effect against MeHg toxicity expressed at the T lymphocyte proliferation level for harbour seals. Selenite and SeMet did not show negative effects regarding lymphocyte proliferation and mitochondrial membrane potential. To conclude, our results clearly demonstrated that MeHg affected in vitro immune cells exposure with no protective effects of selenium at a molar ratio Hg:Se of 1:10 in harbour seals from the North Sea.
authors.affiliation: Laboratory of Oceanology, MARE Center, University of Liège, B6c, Allée du 6 Août 15, 4000 Liège, Belgium. Electronic address: krishna.das@ulg.ac.be.
authors.forename: Krishna
authors.initials: K
authors.lastname: Das
authors.affiliation: Laboratory of Oceanology, MARE Center, University of Liège, B6c, Allée du 6 Août 15, 4000 Liège, Belgium.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Dupont
authors.affiliation: Laboratory of Mammalian Cell Culture (GIGA-R), University of Liège, B6c, Allée du 6 Août 15, 4000 Liège, Belgium.
authors.forename: Marie-Claire
authors.initials: MC
authors.lastname: De Pauw-Gillet
authors.affiliation: Institute of Life Sciences, Université catholique de Louvain, Croix du Sud 2/L7.05.08, B-1348 Louvain-la-Neuve, Belgium.
authors.forename: Cathy
authors.initials: C
authors.lastname: Debier
authors.affiliation: Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstrasse 6, 25761 Buesum, Germany.
authors.forename: Ursula
authors.initials: U
authors.lastname: Siebert
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D002478:Cells, Cultured; D007962:Leukocytes / Q000187:drug effects*; D053078:Membrane Potential, Mitochondrial; D008628:Mercury / Q000633:toxicity; D008767:Methylmercury Compounds / Q000633:toxicity*; D046049:Phoca; D012643:Selenium / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D008767:Methylmercury Compounds; D014874:Water Pollutants, Chemical; D008628:Mercury; D012643:Selenium
keywords: Harbour seal; In vitro approach; Lymphocytes; Marine mammals; Methylmercury; Phoca vitulina; Selenium