title: Dynamics of uptake and elimination of pyrethroid insecticides in zebrafish (Danio rerio) eleutheroembryos.
abstract: Synthetic pyrethroids (SPs) are among the most heavily used insecticides for residential and agricultural applications. Their residues have frequently been detected in aquatic ecosystems. Despite their high aquatic toxicity, their toxicokinetics are still unclear. In this study, the kinetics of uptake and depuration of three SPs, permethrin (PM), bifenthrin (BF) and λ-cyhalothrin (λ-CH), were determined for the first time using zebrafish eleutheroembryo assays. The diastereoisomer selectivity of PM in eleutheroembryos was further examined. The results indicated that three SPs were quickly taken up by eleutheroembryos. The bioaccumulation factors of the SPs ranged from 125.4 to 708.4. The depuration of SPs in zebrafish eleutheroembryos followed the first-order process. The elimination rate constants (k2) of SPs in eleutheroembryos ranged from 0.018 h(-1) to 0.0533 h(-1). The half-lives (t1/2) were in the range 13.0-38.5h. The diastereoisomer fraction (DF) values for PM in the eleutheroembryos estimated at different uptake and depuration times were all significantly greater than the original value (DF=0.43), indicating selective enrichment and elimination of cis-PM relative to trans-PM. These results reveal a high capacity for SP bioconcentration by zebrafish eleutheroembryos, suggesting that SPs possess a highly cumulative risk to fish.
authors: International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032, China.
authors: Wenqing
authors: W
authors: Tu
authors: International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032, China.
authors: Bin
authors: B
authors: Lu
authors: IJRC-PTS, MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
authors: Lili
authors: L
authors: Niu
authors: International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032, China. Electronic address: chaoxu@zjut.edu.cn.
authors: Chao
authors: C
authors: Xu
authors: International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032, China.
authors: Chunmian
authors: C
authors: Lin
authors: IJRC-PTS, MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
authors: Weiping
authors: W
authors: Liu
mesh_terms: D000818:Animals; D004625:Embryo, Nonmammalian / Q000378:metabolism; D007306:Insecticides / Q000493:pharmacokinetics*; D009570:Nitriles / Q000493:pharmacokinetics; D026023:Permethrin / Q000493:pharmacokinetics; D011722:Pyrethrins / Q000493:pharmacokinetics*; D015027:Zebrafish / Q000378:metabolism*
chemical_list: D007306:Insecticides; D009570:Nitriles; D011722:Pyrethrins; D026023:Permethrin; C099952:bifenthrin; C037304:cyhalothrin
keywords: Bioconcentration factor (BCF); Pyrethroid insecticides; Uptake and elimination; Zebrafish eleutheroembryo