Effects of Methylmercury on Harbour Seal Peripheral Blood Leucocytes In Vitro Studied by Electron Microscopy.
Methylmercury (MeHg) is highly immunotoxic and can alter the health status of the harbour seal, Phoca vitulina, from the North Sea. To investigate the mechanism of MeHg-induced toxicity in harbour seal lymphocytes, Concanavalin A (ConA)-stimulated peripheral blood leucocytes were exposed in vitro to sublethal concentrations of MeHgCl (0.2, 1, and 2 µM) for 72 h and then analysed for their viability and ultrastructure. After 72 h of incubation, cells were counted with a propidium iodide staining technique, a metabolic MTS assay was performed, and cells exposed to 1 µM of MeHgCl were observed by transmission electron microscopy (TEM). Alive cell numbers decreased with increased MeHgCl concentrations. In presence of ConA and 1 µM of MeHgCl, TEM images revealed a higher frequency of apoptotic cells. Exposed cells displayed condensation of the chromatin at the nuclear membrane and mitochondrial damages. The results suggest that in vitro MeHgCl-induced apoptosis in harbour seal lymphocytes through a mitochondrial pathway.
Laboratory of Oceanology - MARE Center, University of Liege, B6c, Liège, Belgium.
Aurélie
A
Dupont
Mammalian Cell Culture Laboratory (GIGA-R), University of Liege, B6c, Liège, Belgium.
Marie-Claire
MC
De Pauw-Gillet
Laboratory of Oceanology - MARE Center, University of Liege, B6c, Liège, Belgium.
Joseph
J
Schnitzler
Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstrasse 6, 25761, Buesum, Germany.
Ursula
U
Siebert
Laboratory of Oceanology - MARE Center, University of Liege, B6c, Liège, Belgium. krishna.Das@ulg.ac.be.
Krishna
K
Das
D000818:Animals; D066298:In Vitro Techniques; D008214:Lymphocytes / Q000187:drug effects*; D008767:Methylmercury Compounds / Q000633:toxicity*; D008854:Microscopy, Electron; D046049:Phoca; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D008767:Methylmercury Compounds; D014874:Water Pollutants, Chemical