title: Modelling uptake and toxicity of nickel in solution to Enchytraeus crypticus with biotic ligand model theory.
abstract: Protons and other cations may inhibit metal uptake and alleviate metal toxicity in aquatic organisms, but less is known about these interactions in soil organisms. The present study investigated the influence of solution chemistry on uptake and toxicity of Ni in Enchytraeus crypticus after 14 days exposure. Ca(2+), Mg(2+) and Na(+) were found to exert significant effects on both uptake and toxicity of Ni. An extended Langmuir model, which incorporated cation competition effects, well predicted Ni uptake. The LC50{Ni(2+)} predicted by a developed Biotic Ligand Model matched well with observed values. These suggest that cation competition needs to be taken into account when modelling uptake and effects. The binding constants of Ni(2+), Mg(2+) and Na(+) on the uptake and toxic action sites were similar, but for Ca(2+) they differed. This indicates that the effect of Ca(2+) on Ni(2+) toxicity cannot simply be explained by the competition for entry into organism.
authors: Department of Ecological Science, Faculty of Earth and Life Sciences, VU University, De Boelelaan 1085, 1081HV Amsterdam, The Netherlands.
authors: Erkai
authors: E
authors: He
authors: Institute of Environmental Sciences, Leiden University, Leiden, The Netherlands.
authors: Hao
authors: H
authors: Qiu
authors: Department of Ecological Science, Faculty of Earth and Life Sciences, VU University, De Boelelaan 1085, 1081HV Amsterdam, The Netherlands. Electronic address: kees.van.gestel@vu.nl.
authors: Cornelis A M
authors: CA
authors: Van Gestel
mesh_terms: D000818:Animals; D008024:Ligands; D008954:Models, Biological; D008956:Models, Chemical; D009532:Nickel / Q000378:metabolism* / Q000633:toxicity; D009835:Oligochaeta / Q000378:metabolism*; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000378:metabolism* / Q000633:toxicity
chemical_list: D008024:Ligands; D012987:Soil; D012989:Soil Pollutants; D009532:Nickel
keywords: Biotic Ligand Model; Langmuir model; Nickel; Toxicity; Uptake