Influence of metal exposure history on the bioaccumulation and subcellular distribution of aqueous cadmium in the insect Hydropsyche californica

Cain, D. J.; Buchwalter, D. B.; Luoma, S. N.

Abstract:

The influence of metal exposure history on rates of aqueous Cd accumulation, elimination, and subcellular distribution was examined in the aquatic insect Hydropsyche californica. Specimens were obtained from a reference site and a metal-contaminated site and returned to the laboratory where they were continuously exposed to aqueous Cd (518 ng/L, nominal) for 6 d, followed by 9 d of depuration. Rates of Cd accumulation and elimination were similar in insects from the two sites. Efflux rate constants, ke, ranged from 0.20 to 0.24/d (t1/2 ??? 3 d). Immediately following exposure, the cytosol accounted for 40% of the body burden in insects from both sites; however, 89 ?? 2% of the cytosolic Cd was associated with metallothionein-like proteins (MTLP) in insects from the contaminated site, compared to 60 ?? 0% in insects from the reference site. The concentration of Cd bound to non-MTLPs (representing potentially Cd-sensitive proteins) was significantly greater in the insects from the reference site (134 ?? 7 ng/g) than in those from the contaminated site (42 ?? 2 ng/g). At the end of the depuration period, 90% of the accumulated Cd body burden had been eliminated, and Cd concentrations in MTLPs and non-MTLPs were similar between the sites. Results suggested that differences in exposure history had no influence on the bioaccumulation of Cd, but did affect the concentrations of Cd bound to MTLP during Cd exposure in these insects. ?? 2006 SETAC.

Genre:

Article

ProdID:

70030551

Citation Author:

Cain, D. J.; Buchwalter, D. B.; Luoma, S. N.

Citation Contributing Office:

Citation Datum:

Citation Day:

Citation Edition:

Citation Editor:

Citation End Page:

1049

Citation Issue:

Citation Keywords:

Citation Language:

English

Citation Larger Work Title:

Environmental Toxicology and Chemistry

Citation LatN:

Citation LatS:

Citation LonE:

Citation LonW:

Citation Month:

Citation No Pagination:

Citation Number Of Pages:

Citation Online Only Flag:

Citation Phsyical Description:

Citation Projection:

Citation Public Comments:

Citation Publisher:

Citation Series:

Citation Series Code:

Citation Series Number:

Citation Search Results Text:

Influence of metal exposure history on the bioaccumulation and subcellular distribution of aqueous cadmium in the insect Hydropsyche californica; 2006; Article; Journal; Environmental Toxicology and Chemistry; Cain, D. J.; Buchwalter, D. B.; Luoma, S. N.