Effects of Methylmercury on Harbour Seal Peripheral Blood Leucocytes In Vitro Studied by Electron Microscopy

• Published in: Archives of Environmental Contamination and Toxicology
• Main Authors: Dupont, Aurélie, De Pauw-Gillet, Marie-Claire, Schnitzler, Joseph, Siebert, Ursula, Das, Krishna
• Other Authors: MARE - Centre Interfacultaire de Recherches en Océanologie - ULiège
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer Science & Business Media B.V. 2016
• Subjects: marine mammals; harbour seal; Phoca vitulina; methylmercury; blood; lymphocytes; in vitro exposure; Life sciences; Environmental sciences & ecology; Aquatic sciences & oceanology; Sciences du vivant; Sciences de l’environnement & écologie; Sciences aquatiques & océanologie
• Online Access: https://orbi.uliege.be/handle/2268/184665; https://doi.org/10.1007/s00244-015-0207-y

peer reviewed 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, ConA-stimulated peripheral blood leucocytes were exposed in vitro to sub-lethal concentrations of MeHgCl (0.2, 1 and 2 µM) for 72h, and then analysed for their viability and ultrastructure. After 72h of incubation, cells were counted with a propidium iodide staining technique, a metabolic MTS assay was performed, and cells exposed to 1 µM MeHgCl were observed by transmission electron microscopy (TEM). Alive cell numbers decreased with increased MeHgCl concentrations. In presence of ConA and 1µM 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.