Tolerance changes of the potworm Enchytraeus albidus after long-term exposure to cadmium.
Cadmium tolerance in Enchytraeus albidus was assessed for non-acclimatised organisms, as well as populations acclimatised for 18 months to 32, 100 and 320 mg Cd/kg dry wt. of standard artificial soil. Despite the increased concentration of metallothionein-like proteins in the acclimatised potworms, no changes in sensitivity to acute and chronic (juvenile production) cadmium toxicity could be observed. The 21-day LC50s ranged from 627 for the non-acclimatised enchytraeids to 748 mg Cd/kg dry wt. for the organisms acclimatised for 18 months to a cadmium concentration of 320 mg/kg dry wt. The 42-day EC50s varied from 96.2 (73.6-115) for the organisms acclimatised to 32 mg Cd/kg dry wt. to 234 (186-290) mg Cd/kg dry wt. for those acclimatised to 100 mg Cd/kg dry wt., while the value was intermediate for the non-acclimatised organisms and those acclimatised to the highest cadmium concentration. The elevated content of metallothionein-like proteins apparently only served for the detoxification of the increased cadmium body burdens.
Lock
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Ghent University, Laboratory of Environmental Toxicology and Aquatic Ecology, Gent, Belgium. koen.lock@rug.ac.be
Janssen
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D000222:Adaptation, Physiological; D000818:Animals; D000845:Annelida / Q000502:physiology*; D002104:Cadmium / Q000493:pharmacokinetics* / Q000494:pharmacology*; D007928:Lethal Dose 50; D008668:Metallothionein / Q000494:pharmacology; D012989:Soil Pollutants / Q000493:pharmacokinetics* / Q000494:pharmacology*; D013997:Time Factors
D012989:Soil Pollutants; D002104:Cadmium; D008668:Metallothionein