Identification of enzymes responsible for dantrolene metabolism in the human liver: A clue to uncover the cause of liver injury
Identification of enzymes responsible for dantrolene metabolism in the human liver: A clue to uncover the cause of liver injury
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DOI：
10.1016/j.bcp.2018.03.002
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发表时间：
2018-05-01
影响因子：
5.8
通讯作者：
Nakajima, Miki
中科院分区：
文献类型：
--
作者：
Amano, Takayuki;Fukami, Tatsuki;Nakajima, Miki
丹曲林用于麻醉期间的恶性高热，有时会导致严重的肝损伤作为副作用。丹曲林代谢为乙酰氨基丹曲林，后者通过丹曲林还原为氨基丹曲林和随后的乙酰化形成。代谢过程中羟胺的形成可能与肝损伤有关。我们确定了人体中负责丹曲林代谢的酶，以阐明肝损伤的机制。在人肝微粒体中未检测到丹曲林还原酶活性，但在胞质溶胶中检测到。在N-1-甲基烟酰胺的存在下，这是一个电子供体醛氧化酶1（AOX 1）的形成增加。AOX 1的有效抑制剂和与AOX 1活性标志物（即酞嗪氧化酶活性）的相关性研究，在一组28份人肝细胞溶质样本中支持AOX 1在丹曲林减少中的作用。在重组N-乙酰转移酶（NAT）2而不是NATI中高度检测到氨基丹曲林形成乙酰氨基丹曲林。谷胱甘肽捕获试验显示，通过AOX 1依赖性还原丹曲林而不是通过羟基化氨基丹曲林形成羟胺。总之，我们发现AOX 1和NAT 2负责人体丹曲林代谢，AOX 1依赖性代谢决定丹曲林诱导的肝损伤。
Dantrolene is used for malignant hyperthermia during anesthesia, and it sometimes causes severe liver injury as a side effect. Dantrolene is metabolized to acetylaminodantrolene, which is formed via the reduction of dantrolene to aminodantrolene and subsequent acetylation. Formation of hydroxylamine during the metabolic process may be associated with liver injury. We identified the enzymes responsible for dantrolene metabolism in humans to elucidate the mechanism of liver injury. Dantrolene reductase activity was not detected in human liver microsomes, but it was detected in cytosol. Formation was increased in the presence of N-1-methylnicotineamide, which is an electron donor to aldehyde oxidase 1 (AOX1). Potent inhibitors of AOX1 and a correlation study with a marker of AOX1 activity, namely phthalazine oxidase activity, in a panel of 28 human liver cytosol samples supported the role of AOX1 in dantrolene reduction. Acetylaminodantrolene formation from aminodantrolene was highly detected in recombinant N-acetyltransferase (NAT) 2 rather than NATI. A glutathione trapping assay revealed the formation of hydroxylamine via an AOX1-dependent reduction of dantrolene but not via hydroxylation of aminodantrolene. In conclusion, we found that AOX1 and NAT2 were responsible for dantrolene metabolism in humans and that AOX1-dependent metabolism determines dantrolene-induced liver injury.