Reduction of 1,3-diphenyl-1-triazene by rat hepatic microsomes, by cecal microflora, and in rats generates the phenyl radical metabolite: nn ESR spin-trapping investigation.
Reduction of 1,3-diphenyl-1-triazene by rat hepatic microsomes, by cecal microflora, and in rats generates the phenyl radical metabolite: nn ESR spin-trapping investigation.
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DOI：
10.1021/tx000098v
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发表时间：
2000-10
影响因子：
4.1
通讯作者：
M. Kadiiska;K. S. De Costa;R. Mason;J. Mathews
中科院分区：
文献类型：
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作者：
M. Kadiiska;K. S. De Costa;R. Mason;J. Mathews
ESR自旋捕集技术被用来确定是否形成自由基代谢物的结果，在体内和体外的1，3-二苯基-1-三氮烯（DPT）的微粒体中的细胞色素P450（P450）的混合功能氧化酶系统的组件或肠道微生物菌群在厌氧盲肠孵育。在含有DPT、DMPO和NADPH的微粒体孵育中检测到DMPO-苯基自由基加合物的ESR谱，其超精细偶联常数为：a（N）= 15.95 G和= 24.37 G。从DPT与DMPO和NADPH的微粒体孵育中产生的苯基自由基加合物的光谱的振幅没有衰减的P450抑制剂1-氨基苯并三唑（ABT）或一氧化碳，表明P450是不显着参与苯基自由基的形成。DMPO-苯基自由基加合物的形成也被重组人细胞色素P450还原酶催化。添加抗大鼠P450还原酶抗体导致在含有微粒体或还原酶的孵育物中信号减弱。在含有DPT和自旋捕集器的盲肠内容物的甲苯提取物中，通过ESR检测到低浓度的DMPO-苯基自由基加合物。在用DPT和自旋捕集剂DMPO处理的大鼠的体内实验中，在用DPT和DMPO处理大鼠后40-60分钟，在胆汁中容易地检测到DMPO-苯基自由基加合物的六线ESR信号。结果首次表明，苯基自由基是由DPT还原形成的，并可能表明这种化学品的毒性潜力。
An ESR spin-trapping technique was used to determine whether free radical metabolites are formed as a result of the reduction of 1, 3-diphenyl-1-triazene (DPT) in vivo and in vitro by components of the cytochrome P450 (P450) mixed-function oxidase system in microsomes or by gut microflora in anaerobic cecal incubations. The ESR spectrum of the DMPO-phenyl radical adduct was detected in a microsomal incubation containing DPT, DMPO, and NADPH with the following hyperfine coupling constants: a(N) = 15.95 G and = 24.37 G. The amplitude of the spectrum from the phenyl radical adduct generated in microsomal incubations of DPT with DMPO and NADPH was not attenuated by the P450 inhibitor 1-aminobenzotriazole (ABT) or by carbon monoxide, indicating that P450 is not significantly involved in phenyl radical formation. The formation of a DMPO-phenyl radical adduct was also catalyzed by recombinant human cytochrome P450 reductase. Addition of anti-rat P450 reductase antibody led to an attenuation of the signal in incubations containing either microsomes or reductase. Low concentrations of DMPO-phenyl radical adducts were detected by ESR in the toluene extract of cecal contents containing DPT and the spin trap. In the in vivo experiments with rats treated with DPT and the spin trap DMPO, the six-line ESR signal of the DMPO-phenyl radical adduct was readily detected in bile 40-60 min after rats were treated with DPT and DMPO. The results show for the first time that the phenyl radical is formed by the reduction of DPT and may indicate a toxic potential for this chemical.