The drug-induced hepatotoxicity

采用肝微粒体、分离肝细胞、原代培养肝细胞和肝组织，研究药物肝毒性对氧化应激和反应代谢产物的影响，并用化学发光法研究药物诱导的氧化应激。建立了化学发光-高效液相色谱联用系统，对药物代谢过程中产生的过氧化脂质进行了检测。用乙氰酸孵育的大鼠肝微粒体和肝细胞悬液中检测到磷脂酰胆碱过氧化氢(PCOOH)。观察到PCOOH的生成早于硫代巴比妥酸反应物质(TBARS)的生成。超微弱的化学发光是直接从肝微粒体和分离的肝细胞与乙氰酸孵育。这伴随着分离的肝细胞释放乳酸脱氢酶。此外，我们建立了器官化学发光体系，并成功地检测到了乙氰酸灌流的大鼠肝脏发出的超弱化学发光。这一结果证实了乙炔酸诱导的肝脏氧化应激。这些从化学发光检测系统获得的结果被发现与谷胱甘肽的变化密切相关。因此，化学发光系统可以检测到药物代谢引起的氧化应激，具有很高的灵敏度和特异度。双肼肼可引起免疫性肝炎，而CYP1A2被认为是其反应代谢产物的靶蛋白。此外，在大鼠和人肝微粒体中发现了其靶蛋白--CYP3A4。丙咪嗪和米安色林的肝毒性与其反应性代谢产物密切相关。二苯胺结构在非甾体抗炎药肝毒性中起重要作用。具有二苯胺结构的非甾体抗炎药是氧化磷酸化的解偶联剂。

The drug-induced hepatotoxicity was studied on the oxidative stress and reactive metabolites, using liver microsomes, isolated hepatocytes, primary cultured hepatocytes and liver tissues.The chemiluminescence was used to investigate the drug-induced oxidative stress. The chemiluminescence-HPLC system was set up and we tried to measure the lipid peroxides produced during the drug metabolism. And phosphatidyl choline hydroperoxide (PCOOH) was detected in the rat liver microsome and isolated hepatocyte suspension incubated with ethacrynic acid. It was observed that PCOOH was produced earlier than the thiobarbituric acid reactive substances (TBARS) formation. The ultraweak chemiluminescence was shown to be emitted directly from the liver microsomes and isolated hepatocytes incubated with ethacrynic acid. This was accompanied by the LDH release from the isolated hepatocytes. Further, we set up the organ chemiluminescence system and succeeded in detecting the ultraweak chemiluminescence emitted from the rat liver perfused with ethacrynic acid. This result substantiated the ethacrynic acid-induced oxidative stress in the liver. These results obtained from the chemiluminescence detection systems were found to be related closely with the alteration in glutathione. Thus the oxidative stress due to the drug metabolism was shown to be detectable by the chemiluminescence system with high sensitivity and specificity.Dihydralazine is known to cause the immunohepatitis and CYP1A2 is reported as a target protein of its reactive metabolite. In addition, CYP3A4 was found to be its target protein in rat and human liver microsomes. The imipramine- and mianserin-induced hepatotoxicity was shown to be closely related with their reactive metabolites. The diphenylamine structure was found to play an important role in the nonsteroidal anti-inflammatory drug-induced hepatotoxicity. The NSAIDs with diphenylamine structure were shown to be uncouplers of oxidative phosphorylation.