大鼠经胃和皮下暴露毒死蜱的毒物代谢动力学和毒效学模型构建

摘要

OBJECTIVE To develop and validate a physiologically based toxicokinetics and toxico⁃dynamics(PBTK/TD)model for chlorpyrifos(CPF)in rats following both oral and subcutaneous expo⁃sures to CPF. METHODS ①A PBTK/TD model was established with toxicokinetics and toxicodynam⁃ics data in literature,which was used for predicting contents of CPF and 3,5,6-trichloro-2-pyridinol (TCP)in blood and activities of acetylcholine esterase(AChE)in the plasma and brain of rats exposed to CPF.②Rats were given 50 mg · kg-1 CPF oral and 50 mg · kg-1 CPF sc simultaneously. Blood and brain samples were collected at 0,1,2,4,6,8,12,24 and 48 h,respectively,after CPF administration (n=5). CPF And TCP contents in plasma,activities of AChE in the plasma and brain were deter⁃mined,and compared with the simulation values by PBTK/TD model in order to validate the accuracy of the model. RESULTS It was predicted by the PBTK/TD model that after the administration (oral+sc) of CPF 20+20,10+30 and (30+10)mg · kg-1,the concentrations of CPF and TCP in plasma increased and then decreased with time in each group. The inhibitory level of AChE activity in the plasma was orally dose-dependent,while AChE activity of the brain was more sensitive to CPF subcutaneous exposure. The simulation values obtained by the PBTK/TD model were not significantly different from the experimental values obtained by co-administered CPF at(50+50)mg · kg-1. CONCLUSION This CPF PBTK/TD model can quantitatively estimate target tissue dosimetry and AChE inhibition.%目的：构建毒死蜱（CPF）同时ig和sc暴露的以生理学为基础的毒物代谢动力学和毒效学（PBTK/TD）模型，模拟和验证其预测CPF暴露后体内毒代特征及毒效可靠性。方法①构建CPF的PBTK/TD模型，运用所构建的模型模拟大鼠同时ig和sc暴露CPF的毒代和毒效学数据，预测暴露大鼠血液中CPF及其代谢物3，5，6-三氯-2-吡啶酚（TCP）浓度变化，血液和大脑中乙酰胆碱酯酶（AChE）活性变化曲线。②45只成年雄性大鼠一次性ig和sc联合染毒CPF（50+50）mg·kg-1，染毒后0.0，1.0，2.0，4.0，6.0，8.0，12.0，24.0和48.0 h收集生物样本，测定血浆CPF和TCP浓度，及血浆和大脑皮质AChE活性，将实测值与模型模拟值进行比较，以验证模型的准确性。结果模拟大鼠ig和sc联合暴露CPF 20+20，10+30和（30+10）mg · kg-1后，48 h内血液中CPF和TCP浓度均先上升，达到峰值后随之下降；ig暴露剂量越大，血浆AChE活性下降越快，酶活性抑制程度越重，但酶活性恢复速度很快；大脑AChE活性抑制程度受皮下暴露量的影响较大。实测大鼠联合染毒（50+50）mg·kg-1 CPF后的血浆CPF和TCP浓度，及血浆和大脑皮质AChE活性，与模型预测值基本一致，差异无统计学意义。结论本研究所构建的PBTK/TD模型可预测大鼠同时ig和sc暴露CPF后的体内毒代特征及毒效水平。