Inhibition of UDP-glucose dehydrogenase by 6-thiopurine and its oxidative metabolites: Possible mechanism for its interaction within the bilirubin excretion pathway and 6TP associated liver toxicity
作者:Chamitha J. Weeramange、Cassie M. Binns、Chixiang Chen、Ryan J. Rafferty
DOI:10.1016/j.jpba.2017.12.058
日期:2018.3
fully oxidized at carbon 2 and 8, and highly retained by the body) has a near six-fold increased inhibition towards UDPGDH with a Ki of 7 μM. Inhibition was also observed by 6-thioxanthine (oxidized at carbon 2) and 8-OH-6TP with Ki values of 54 and 14 μM, respectively. Neither 6-thiopurine or its excretion metabolites were shown to inhibit UGT1A1. Our results show that the C2 and C8 positions of 6TP
6-硫嘌呤(6TP)是一种治疗各种疾病的积极处方药,从克罗恩氏病和其他炎性疾病到急性淋巴细胞性白血病和非霍奇金氏白血病,不一而足。尽管6TP具有有益的治疗用途,但据报道其使用也会产生严重的毒性,例如黄疸和肝毒性。尽管已经对毒性产生的方式进行了大量研究。没有人研究抑制对UDP-葡萄糖脱氢酶(UDPGDH)的抑制作用,UDPGDH是负责UDP-葡萄糖醛酸(UDPGA)形成的氧化酶或UDP-葡萄糖醛酸转移酶(UGT1A1),后者负责将胆红素与UDPGA结合排泄。 。未能排出胆红素会导致黄疸和肝毒性。我们建议6TP或其主要的氧化排泄代谢产物抑制这些酶中的一种或两种,从而导致从6TP给药中观察到的毒性。对这些嘌呤的抑制分析表明,6-硫嘌呤对带有K的UDPGDH具有弱至无抑制作用我288μM的关于变化的UDP-葡萄糖,但6- thiouric(初级端代谢物,在碳2和8完全氧化,和由所述主体高度保留的)