6:2氟调羧酸在蚯蚓体内的毒理效应及代谢转化  

Toxicological effects and biotransformation mechanism of 6:2fluorotelomer carboxylic acid(6:2FTCA)in earthworms(Eisenia fetida)

作　　者：宗玉璐 杨丽萍[2] 赵淑艳 ZONG Yu-lu;YANG Li-ping;ZHAO Shu-yan(Key Laboratory of Industrial Ecology and Environmental Engineering,Ministry of Education,School of Ocean Science and Technology,Dalian University of Technology,Panjin 124221,China;School of Environmental Science and Engineering,Nankai University,Tianjin 300071,China)

机构地区：[1]大连理工大学海洋科学与技术学院,工业生态与环境工程教育部重点实验室,辽宁盘锦124221 [2]南开大学环境科学与工程学院,天津300071

出　　处：《中国环境科学》2022年第6期2886-2893,共8页China Environmental Science

基　　金：国家自然科学基金项目(41603106,42177374);中央高校基本科研业务费专项(DUT21JC42)。

摘　　要：以赤子爱胜蚓(Eisenia fetida)为受试生物,通过活体与离体实验,研究6:2氟调羧酸(6:2FTCA)在蚯蚓体内的毒理效应和代谢转化机制.结果表明,6:2FTCA对蚯蚓体内丙二醛(MDA)含量和过氧化物酶(POD)活性无显著影响,但能够使过氧化氢酶(CAT)活性提高,使超氧化物歧化酶(SOD)和谷胱甘肽转移酶(GST)活性显著升高,说明6:2FTCA对蚯蚓产生了氧化胁迫效应.6:2FTCA在蚯蚓细胞色素P450(CYP450)和GST酶提取液中的降解动力学均符合一级动力学模型,在CYP450(0.014/h)酶液中的降解速率明显高于GST(0.006/h),其终端全氟羧酸(PFCAs)代谢产物为全氟己酸(PFHxA)、全氟戊酸(PFPeA)和全氟丁酸(PFBA),说明CYP450和GST参与了6:2FTCA在蚯蚓体内的代谢转化,且CYP450贡献大于GST.蚯蚓肠道好氧微生物对6:2FTCA具有显著的降解效果,终端PFCAs降解产物为PFHxA和PFPeA,而肠道厌氧微生物对6:2FTCA无降解作用.Earthworms(Eisenia fetida)were exposed to the soil spiked with 6:2 fluorotelomeric carboxylic acid(6:2 FTCA)to investigate the toxicological effects and biotransformation mechanisms of 6:2 FTCA in earthworms after in vivo and in vitro exposure.Compared to the controls,no significant effects were observed in malondialdehyde(MDA)contents and peroxidase(POD)activities,while catalase(CAT)activities were increased,and superoxide dismutase(SOD)and glutathione-s-transferase(GST)activities were significantly induced in 6:2 FTCA treatments.This suggested that 6:2 FTCA induced oxidative stress in the earthworm cells.Biodegradation of 6:2 FTCA in the earthworm cytolchrome P450(CYP450)enzyme extracts and GST enzyme extracts fitted well with the first order kinetics.The biodegradation rate in CYP450 extracts(0.014/h)was much higher than that in GST extracts(0.006/h),indicating CYP450 and GST were involved in the enzymatic transformation and CYP450 contributed more than GST to 6:2 FTCA biotrans formation in earthworms.Three terminal perfluorocarboxylic acid(PFCA)metabolites,including perfluorohexanoic acid(PFHxA),perfluoropentanoic acid(PFPeA)and perfluorobutanoic acid(PFBA)were observed in the enzyme extracts.The results of gut microbial degradation test showed that aerobic microorganisms contributed to 6:2 FTCA biodegradation in earthworms significantly,and the terminal PFCA metabolites were PFHxA and PFPeA,but anaerobic microorganisms didn’t contribute to 6:2 FTCA biotransformation in earthworms.

关 键 词：6:2氟调羧酸 蚯蚓 毒理效应 酶代谢 肠道微生物 

分 类 号：X171.5[环境科学与工程—环境科学]