De Schryver E, De Reu L, Belpaire F, Willems J
Arch Toxicol. 1987 Feb;59(5):319-22. doi: 10.1007/BF00295082.
The toxicokinetics of methyl paraoxon, the active metabolite of the organophosphorus insecticide methyl parathion, were studied in non-anaesthetized dogs after intravenous (2.5 mg/kg) and oral (15 mg/kg) administration of methyl paraoxon. After intravenous administration, distribution and elimination occurred very rapidly and using the data from 5 min post-injection, the plasma concentration versus time curves could be fitted to a one-compartment open model. The mean half-life of elimination was 9.7 min, the average volume of distribution 1.76 l/kg and the average plasma clearance 126 ml/kg/min. After oral administration, peak plasma concentrations were obtained within 3-16 min, and the bioavailability varied from 5 to 71%. The hepatic extraction of methyl paraoxon measured in anaesthetized dogs, was high (70-92%). Comparison of the urinary excretion after intravenous and oral administration in two dogs indicated a gastrointestinal absorption of more than 60%. The kinetics of methyl paraoxon were linear in the dose range tested.
对有机磷杀虫剂甲基对硫磷的活性代谢产物甲基对氧磷，在非麻醉犬静脉注射（2.5毫克/千克）和口服（15毫克/千克）后进行了毒代动力学研究。静脉注射后，分布和消除非常迅速，利用注射后5分钟的数据，血浆浓度-时间曲线可拟合为一室开放模型。消除的平均半衰期为9.7分钟，平均分布容积为1.76升/千克，平均血浆清除率为126毫升/千克/分钟。口服后，血浆浓度在3 - 16分钟内达到峰值，生物利用度在5%至71%之间变化。在麻醉犬中测得的甲基对氧磷的肝提取率很高（70 - 92%）。对两只犬静脉注射和口服后的尿排泄情况进行比较，表明胃肠道吸收率超过60%。在所测试的剂量范围内，甲基对氧磷的动力学呈线性。
