Dannesboe Johs, Bastrup Joakim A, Nielsen Kathrine Holm, Munck Pelle, Thomsen Morten B, Hawkins Clare L, Jepps Thomas A
Department of Biomedical Sciences, University of Copenhagen, Blegdamsvej 3, Copenhagen N 2200, Denmark.
Department of Biomedical Sciences, University of Copenhagen, Blegdamsvej 3, Copenhagen N 2200, Denmark.
Pharmacol Res. 2025 Jan;211:107540. doi: 10.1016/j.phrs.2024.107540. Epub 2024 Dec 7.
It was shown previously that a metabolite of acetaminophen (APAP), N-acetyl-p-benzoquinone imine (NAPQI), is a potent vasodilator, which could underlie the hypotension observed when APAP is administered intravenously. However, it is unknown whether APAP metabolism to NAPQI is possible in the vasculature. In this study, we examine the hypothesis that APAP is metabolized by cytochrome P450 enzymes within the endothelium, which may be accelerated in critically ill patients by the presence of elevated myeloperoxidase (MPO). Exposure of human coronary artery endothelial cells (HCAECs) to APAP resulted in the formation of protein-bound APAP adducts. Proteomic analysis of HCAECs exposed to APAP showed upregulation of CYP20A1, together with proteins involved in the pentose phosphate pathway and maintaining redox homeostasis. Proteomic analyses of mesenteric arteries from rats administered intravenous APAP are consistent with a key role of the vascular wall in APAP metabolism, with similar proteomic pathway changes identified in HCAECs. These changes occurred over a short timeframe and were not seen in the corresponding proteomic analyses of liver tissue. Intracellular thiols were depleted in HCAECs upon APAP treatment, which was partially attenuated by ketoconazole, consistent with the involvement of cytochrome P450 enzymes in the metabolism of APAP to a thiol-reactive metabolite such as NAPQI. Evidence was also obtained for the metabolism of APAP to a thiol-reactive intermediate by MPO in the absence of chloride ions, consistent with NAPQI formation. Taken together, these data provide a putative mechanism to explain the presentation of hypotension in critically ill patients following IV APAP administration.
先前的研究表明，对乙酰氨基酚（APAP）的一种代谢产物N-乙酰对苯醌亚胺（NAPQI）是一种强效血管舒张剂，这可能是静脉注射APAP时出现低血压的原因。然而，尚不清楚APAP在血管系统中是否可能代谢为NAPQI。在本研究中，我们检验了以下假设：APAP在内皮细胞内被细胞色素P450酶代谢，而在危重症患者中，由于髓过氧化物酶（MPO）水平升高，这种代谢可能会加速。将人冠状动脉内皮细胞（HCAECs）暴露于APAP会导致形成与蛋白质结合的APAP加合物。对暴露于APAP的HCAECs进行蛋白质组学分析，结果显示CYP20A1上调，同时戊糖磷酸途径和维持氧化还原稳态的相关蛋白质也上调。对静脉注射APAP的大鼠肠系膜动脉进行蛋白质组学分析，结果与血管壁在APAP代谢中的关键作用一致，在HCAECs中也发现了类似的蛋白质组学途径变化。这些变化发生在短时间内，在肝脏组织的相应蛋白质组学分析中未观察到。APAP处理后，HCAECs中的细胞内硫醇减少，酮康唑可部分缓解这种情况，这与细胞色素P450酶参与将APAP代谢为硫醇反应性代谢产物（如NAPQI）一致。在没有氯离子的情况下，还获得了MPO将APAP代谢为硫醇反应性中间体的证据，这与NAPQI的形成一致。综上所述，这些数据提供了一种推测机制，以解释危重症患者静脉注射APAP后出现低血压的情况。
