Page 105 - 南京医科大学学报自然科学版

第42卷第3期 南京医科大学学报（自然科学版）
2022年3月 Journal of Nanjing Medical University（Natural Sciences） ·407 ·

·公共卫生与预防医学研究·

CYP2B6对农药p，p’⁃DDT的代谢活性及代谢产物解析

徐抒语 ，李书书 ，王 丽 ，王 超 ，王守林 1，2*
2
2
2*
1，2
南京医科大学生殖医学国家重点实验室，公共卫生学院现代毒理学教育部重点实验室，江苏 南京 211166
1 2
［摘 要］ 目的：本研究选择细胞色素P450酶（cytochrome P450，CYP）2B6介导p，p’⁃滴滴涕（dichloro⁃diphenyl⁃trichloroethane，
DDT）生物转化过程进行研究，为该类持久性有机污染物的风险评估和防治提供依据。方法：建立气相色谱/质谱联用仪（GC⁃
MS/MS）的检测方法以检测生物样本中的p，p’⁃DDT；利用重组酶CYP2B6构建体外代谢模型，采用米式方程计算代谢动力学参
数；采用抑制剂8⁃MOP 验证CYP2B6对p，p’⁃DDT 的代谢能力；构建SD大鼠体内代谢模型（大鼠CYP2B1是人CYP2B6的同源
酶），尾静脉注射p，p’⁃DDT和CYP2B6的特异性抑制剂KR⁃Ⅱ，收集血清（0、5、10、20、30 min）以及肝脏微粒体，比较对照组以
及抑制剂组大鼠肝脏中CYP2B1活性以及肝脏和血清中p，p’⁃DDT原形及代谢产物p，p’⁃DDE、p，p’⁃DDD水平的变化。结果：
成功建立了多种DDT及代谢产物的 GC⁃MS/MS检测方法。体外代谢证实CYP2B6可代谢p，p’⁃DDT产生以p，p’⁃DDE为主的
代谢产物，动力学参数Km为15.12 μmol/L，每纳摩尔P450酶的Vmax为12.8nmol/min；抑制剂8⁃MOP可显著抑制CYP2B6活性，代
谢产物p，p’⁃DDE的含量显著下降。CYP2B1表达被抑制后，大鼠肝脏中CYP2B1的酶活性显著下降，肝脏和血清中的代谢产
物p，p’⁃DDE和p，p’⁃DDD含量也明显降低。结论：CYP2B6可以代谢p，p’⁃DDT生成以p，p’⁃DDE为主的代谢产物，是DDT的
主要优势代谢酶。考虑到人群中CYP2B6的表达和活性存在差异，本研究可为DDT暴露危害的易感人群筛选及风险评估的优
化提供依据。
［关键词］ 有机氯农药；滴滴涕；CYP2B6；生物转化；代谢产物
［中图分类号］ R139.3 ［文献标志码］ A ［文章编号］ 1007⁃4368（2022）03⁃407⁃08
doi：10.7655/NYDXBNS20220317

Metabolic activity of CYP2B6 on pesticide p，p’⁃DDT and analysis of its metabolites
2*
1，2
2
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XU Shuyu ，LI Shushu ，WANG Li ，WANG Chao ，WANG Shoulin 1，2*
1 2
State Key Lab of Reproductive Medicine，Key Lab of Modern Toxicology of Ministry of Education，School of Public
Health，Nanjing Medical University，Nanjing 211166，China
［Abstract］ Objective：This study is proposed to clarify the biological conversion process of p，p’⁃dichloro⁃diphenyl⁃trichloroethane
（DDT）metabolized by cytochrome P450（CYP）2B6. The result will provide basis for the risk assessment and prevention of persistent
organic pollutant. Methods：The detection method based on gas chromatography⁃mass spectrometry（GC⁃MS/MS）was established to
detect DDT in biological samples. The metabolic model in vitro was established，using recombinant enzyme CYP2B6 and p，p’⁃DDT.
The enzyme activity was calculated by Michaelis⁃Menten equation. The 8⁃MOP as enzyme inhibitor was used to verify the metabolical
ability of CYP2B6 on p，p’⁃ DDT. Meanwhile，the metabolic model in vivo was established in SD rat（rat CYP2B1 is homologous
enzymes of human CYP2B6）by tail intravenous injection of p，p’⁃DDT and CYP2B6 specific chemical inhibitor KR⁃Ⅱ. The changes
of p，p’⁃DDT prototypes and metabolites（p，p’⁃DDE，p，p’⁃DDD）and the changes of enzyme activity were assessed in the serum（0
min，5 min，10 min，20 min，30 min）and liver microsomes. Results：A detection method for DDT was successfully established and
tested. Metabolic experiments in vitro confirmed that p，p’⁃DDT could metabolized by CYP2B6，and the main metabolite was p，p’⁃
DDE. Kinetic parameter K m was 15.12 μmol/L，and the Vmax of per nanomolar P450 is 12.8 nmol/min. Inhibitor 8⁃MOP significantly
inhibited the CYP2B6 activity and metabolites p，p’⁃DDE content significantly decreased. After CYP2B1 was inhibited，the metabolic
enzyme activity was significantly decreased and the serum p，p’⁃DDE and p，p’⁃DDD product content was lowered. Conclusion：
CYP2B6 can metabolize p，p’⁃DDT to produce metabolites dominated by p，p’⁃DDE，and it should be the dominant enzyme of DDT in
the human body. Considering that there are differences in the expression and activity of CYP2B6. This study can provide a basis for
［基金项目］ 国家自然科学基金（91743205，81903353，81803198）
∗
通信作者（Corresponding author），E⁃mail：wangchao@njmu.edu.cn；wangshl@njmu.edu.cn