代谢
N,N-二甲基甲酰胺(DMF)通过微粒体细胞色素P-450代谢,主要转化为N-羟甲基-N-甲基甲酰胺(HMMF),后者进一步分解为N-甲基甲酰胺(NMF)。然而,其毒性作用的详细机制尚不清楚。我们使用离体灌流肝脏模型研究了DMF的代谢和毒性。将DMF以0、10和25 mM的浓度添加到离体灌流大鼠肝脏的循环灌流液中。在加入DMF后0、30、45、60、75和90分钟从下腔静脉收集样本。使用气相色谱(GC)分析DMF的代谢物。在灌流过程中监测DMF耗氧率的变化。监测灌流液中的酶活性(天冬氨酸转氨酶:AST,丙氨酸转氨酶:ALT,乳酸脱氢酶:LDH),以观察DMF是否引起肝毒性。随着灌流的进行,灌流液中DMF的浓度降低,但NMF的水平升高到最大1.16 mM。在DMF浓度为10 mM和25 mM时,耗氧率增加。然而,当使用已知细胞色素P-450的抑制剂SKF 525A(300 uM)预处理灌流液,然后加入DMF时,耗氧率显著受到抑制,表明细胞色素P-450系统负责将DMF转化为NMF。加入DMF后,AST、ALT和LDH的活性显著增加,呈现时间和剂量依赖性。然而,经SKF 525A预处理后,它们的释放受到抑制。
N,N-dimethylformamide (DMF) is metabolized by the microsomal cytochrome p-450 into mainly N-hydroxymethyl- N-methylformamide (HMMF), which further breaks down to N-methyformamide (NMF). However, the detailed mechanism of its toxicity remains unclear. We investigated the metabolism and the toxicity of DMF using the isolated perfused liver model. DMF was added to the recirculating perfusate of the isolated perfused rat liver at concentrations of 0, 10 and 25 mM. Samples were collected from the inferior vena cava at 0, 30, 45, 60, 75, and 90 minutes following addition of the DMF. The metabolites of DMF were analyzed using Gas-chromatography (GC). The changes in the rate of oxygen consumption by the DMF were monitored during perfusion. The enzyme activities (aspartic aminotransferase:AST, alanine aminotransferase:ALT, and lactic dehydrogenase:LDH)) in the perfusate were monitored to see if DMF caused hepatotoxicity. As the perfusion progressed, the DMF concentration in the perfusate decreased, but the level of NMF increased to a maximum of 1.16 mM. The rate of oxygen consumption increased at DMF concentrations of 10 mM and 25 mM. However, when a known inhibitor of cytochrome P-450, SKF 525A (300 uM), was used to pretreat the perfusate prior to the addition of the DMF, the rate of oxygen consumption was significantly inhibited, indicating the cytochrome P-450 system was responsible for the conversion of DMF to NMF. On addition of the DMF, the activities of the enzymes AST, ALT and LDH were significantly increased a time and dose dependent manner. However, following pretreatment with SKF 525A, their releases were inhibited.
来源:Hazardous Substances Data Bank (HSDB)