Doerr Adrian A, Nordmeier Frederike, Walle Nadja, Laschke Matthias W, Menger Michael D, Schmidt Peter H, Schaefer Nadine, Meyer Markus R
Institute of Legal Medicine, Saarland University, 66421 Homburg, Germany.
Institute for Clinical and Experimental Surgery, Saarland University, 66421 Homburg, Germany.
J Anal Toxicol. 2021 Jul 10;45(6):593-604. doi: 10.1093/jat/bkaa122.
New psychoactive substances (NPS), especially synthetic cannabinoids (SC) remain a public health concern. Due to ethical reasons, systematic controlled human studies to elucidate their toxicodynamics and/or toxicokinetics are usually not possible. However, such knowledge is necessary, for example, for determination of screening targets and interpretation of clinical and forensic toxicological data. In the present study, the feasibility of the pig model as an alternative for human in vivo metabolism studies of SC was investigated. For this purpose, the metabolic pattern of the SC methyl-2-{[1-(5-fluoropentyl)-1H-pyrrolo[2,3-b]pyridine-3-carbonyl]amino}-3,3-dimethylbutanoate (5F-MDMB-P7AICA) was elucidated in pig urine following inhalative administration (dosage: 200 µg/kg of body weight). The results were compared with human and pig liver microsomal assays and literature. In addition, different incubations with isolated cytochrome-P450 (CYP) monooxygenases were conducted to identify the involved isozymes. In total, nine phase I and three phase II metabolites were identified in pig urine. The most abundant reactions were ester hydrolysis, ester hydrolysis combined with glucuronidation and ester hydrolysis combined with hydroxylation at the tert-butyl moiety. The parent compound was only found up to 1 h after administration in pig urine. The metabolite formed after hydroxylation and glucuronidation was detectable for 2 h, the one formed after ester hydrolyzation and defluorination for 4 h after administration. All other metabolites were detected during the whole sampling time. The most abundant metabolites were also detected using both microsomal incubations and monooxygenase screenings revealed that CYP3A4 catalyzed most reactions. Finally, pig data showed to be in line with published human data. To conclude, the main metabolites recommended in previous studies as urinary targets were confirmed by using pig urine. The used pig model seems therefore to be a suitable alternative for in vivo metabolism studies of 7-azaindole-derived SC.
新型精神活性物质（NPS），尤其是合成大麻素（SC）仍然是一个公共卫生问题。由于伦理原因，通常不可能进行系统的人体对照研究来阐明它们的毒代动力学和/或毒效动力学。然而，例如对于确定筛查靶点以及解释临床和法医毒理学数据而言，此类知识是必要的。在本研究中，研究了猪模型作为人类SC体内代谢研究替代方法的可行性。为此，在吸入给药（剂量：200μg/kg体重）后，对猪尿液中SC甲基-2-{[1-(5-氟戊基)-1H-吡咯并[2,3-b]吡啶-3-羰基]氨基}-3,3-二甲基丁酸酯（5F-MDMB-P7AICA） 的代谢模式进行了阐明。将结果与人和猪肝微粒体测定及文献进行了比较。此外，还进行了与分离的细胞色素P450（CYP）单加氧酶的不同孵育实验，以鉴定所涉及的同工酶。在猪尿液中总共鉴定出9种I相代谢物和3种II相代谢物。最主要的反应是酯水解、酯水解与葡萄糖醛酸化结合以及酯水解与叔丁基部分的羟基化结合。母体化合物在给药后1小时内仅在猪尿液中被发现。羟基化和葡萄糖醛酸化后形成的代谢物在给药后2小时内可检测到，酯水解和脱氟后形成的代谢物在给药后4小时内可检测到。所有其他代谢物在整个采样时间内均被检测到。使用微粒体孵育和单加氧酶筛选也检测到了最主要的代谢物，结果表明CYP3A4催化了大多数反应。最后，猪的数据显示与已发表的人类数据一致。总之，通过使用猪尿液证实了先前研究中推荐作为尿液靶点的主要代谢物。因此，所使用的猪模型似乎是7-氮杂吲哚衍生的SC体内代谢研究的合适替代方法。
