State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, PR China; Chongqing Solid Wastes Management Center, Chongqing 401147, PR China.
State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, Research Group of Emerging Contaminants, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510530, PR China; School of Public Health, Key Laboratory of Environmental Pollution and Disease Monitoring of Ministry of Education, Guizhou Medical University, Guiyang 550000, PR China.
Ecotoxicol Environ Saf. 2023 Jan 1;249:114469. doi: 10.1016/j.ecoenv.2022.114469. Epub 2022 Dec 26.
The tissue-specific bioaccumulation of Dechlorane Plus (DP) isomers was investigated in two predator fish species (redtail catfish, RF; and oscar fish, OF) that were feeding on tiger barb (TB), which was exposed to syn-DP and anti-DP isomers. The biotransformation potential of DP isomers was examined by in vitro metabolism using fish liver microsomes. No difference in accumulation behaviors of DP isomers was observed between RF and OF, and the accumulation of both syn- and anti-DP isomers exhibiting a linear increase trend with the exposure time in all fish tissues. The assimilation efficiencies and depuration rates for syn-DP and anti-DP were determined to be the highest in the liver. Biomagnification factors (BMFs) for both syn-DP and anti-DP were higher than one in the serum and gastrointestinal tract of fish, whereas were less than one in the other tissues. The wet-weight concentrations of DP isomers in tissues were significantly correlated with the lipid contents in both fish species, indicating that the tissue distribution of DP isomers occurred through passive diffusion to the lipid compartments in vivo. Tissue-specific compositions of DP isomers were observed, with anti-DP selectively accumulating in the liver, gonad, serum, and gills, whilst syn-DP in the carcass and GI tract. However, after being normalized of all tissues, the fish showed no selective accumulation of DP isomers during the exposure period, and selective accumulation of syn-DP was observed during the depuration period. No potential DP metabolites were detected in the fish tissues and in vitro metabolism systems. The main cause of this stereoselective DP isomer accumulation could have been the selective excretion of anti-DP isomer through the fish feces.
研究了两种掠食性鱼类（红尾鲶鱼和奥氏红腹鱼）在摄食受 syn-DP 和 anti-DP 异构体污染的虎鱼后，体内 DP 异构体的组织特异性生物累积情况。采用鱼类肝微粒体体外代谢方法研究 DP 异构体的生物转化潜力。RF 和 OF 对 DP 异构体的积累行为没有差异，并且所有鱼类组织中 syn-和 anti-DP 异构体的积累均随暴露时间呈线性增加趋势。 syn-DP 和 anti-DP 的同化效率和清除率在肝脏中最高。 syn-DP 和 anti-DP 的生物放大因子（BMFs）在鱼类的血清和胃肠道中均高于 1，而在其他组织中则低于 1。组织中 DP 异构体的湿重浓度与两种鱼类组织中的脂质含量显著相关，表明 DP 异构体在体内通过被动扩散到脂质区室进行组织分布。观察到 DP 异构体的组织特异性组成， anti-DP 选择性地积累在肝脏、性腺、血清和鳃中，而 syn-DP 则积累在胴体和胃肠道中。然而，在归一化所有组织后，鱼类在暴露期间没有表现出对 DP 异构体的选择性积累，并且在清除期间观察到 syn-DP 的选择性积累。在鱼类组织和体外代谢系统中均未检测到潜在的 DP 代谢物。这种 DP 异构体立体选择性积累的主要原因可能是 anti-DP 异构体通过鱼类粪便的选择性排泄。
