The fate of mercury species injected into coelomic fluid of starfish Leptasterias polaris

✍ Scribed by Sophie Maheu; Emilien Pelletier

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 758 KB
• Volume: 9
• Category: Article
• ISSN: 0268-2605
• DOI: 10.1002/aoc.590090806

✦ Synopsis

Mature starfish Leptasterias polaris, collected in the St Lawrence Estuary (eastern Canada), were exposed to two mercury species (HgCI, and CH,HgCI) via injections into the coelomic fluid. In uiuo effects of some complexing agents (glutathione, mercaptoethanol and EDTA) on the distribution of U"Hg-labelled species in starfish organs and tissues and their possible role in mercury transport through membranes were studied over a 24 h period. The excretion of ammonia and mercury was also measured. When injected alone, inorganic mercury and methylmercury [CH,Hg(II)] were distributed in all organs, with a preferential adsorption in gonads, pyloric caeca and stomach. Mercury excretion was very low under all conditions studied. Mercaptoethanol, a small thiol ligand, was very efficient in reducing both mercury species in the coelomic fluid and seems to have promoted translocation towards most organs of the starfish. Its action is attributed to the formation of small and neutral complexes, HgL, and CH3HgL, which can diffuse through membranes preserving their integrity. Glutathione increased the translocation of CH,Hg(II) towards surrounding organs, but had no apparent effect on inorganic mercury. EDTA promoted the transport of inorganic mercury only. These results highlight (1) the particular interest of starfish to workers studying in uiuo chemical complexation of mercury species, and (2) the potential role of complexing molecules in the biotransport of mercury species through living membranes.