Kupffer cell-independent acute hepatocellular oxidative stress and decreased bile formation in post-cold-ischemic rat liver
Kupffer cell-independent acute hepatocellular oxidative stress and decreased bile formation in post-cold-ischemic rat liver
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DOI：
10.1002/hep.510300601
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发表时间：
1999-12-01
期刊：
影响因子：
13.5
通讯作者：
Kitajima, M
中科院分区：
文献类型：
--
作者：
Kumamoto, Y;Suematsu, M;Kitajima, M
本研究的目的是检查在超急性期的再灌注过程中的肝移植冷缺血的氧化应激的分布和时间的历史，并探讨枯否细胞作为一个潜在的氧化源的作用。在威斯康星州大学溶液中于4 ℃收获大鼠肝脏，然后在监测胆汁排泄的情况下用Krebs-Henseleit缓冲液再灌注。为了研究氧化的变化，激光共聚焦显微荧光照相术进行预载二氯二氢荧光素二乙酸琥珀酰亚胺酯，荧光前体传感细胞内氢过氧化物的产生在再灌注的肝脏。经过16小时冷藏的肝脏显示出胆汁酸依赖性胆汁输出的恢复受损，同时肝细胞中氢过氧化物生成显著增加，这发生在再灌注开始后5分钟，而小叶灌注的状态保持良好。脂质体包封的二氯亚甲基二膦酸盐（一种枯否细胞耗竭剂）预处理既没有改变再灌注诱导的门静脉周围氧化变化，也没有改善移植物中胆汁输出的恢复。另一方面，EPCK，一种由维生素E磷酸酯结合维生素C组成的亲肝抗氧化剂，不仅减少了氧化变化，而且还改善了胆汁酸依赖性胆汁排出量的减少。此外，该试剂能够抑制H2 O2诱导的肝细胞氧化应激。这些结果表明，肝细胞构成了通过库普弗细胞非依赖性机制触发的氧化损伤的主要部位，并作为受抗氧化剂治疗保护的重要细胞成分。
The purpose of this study was to examine distribution and time history of oxidative stress during the hyperacute period of reperfusion in the liver grafts undergoing cold ischemia and to investigate roles of Kupffer cells as a potential oxidant source. Rat Livers were harvested at 4 degrees C in University of Wisconsin solution and followed by reperfusion with Krebs-Henseleit buffer under monitoring bile excretion. To investigate oxidative changes, laser-confocal microfluorography was performed in reperfused livers preloaded with dichlorodihydrofluorescein diacetate succinimidyl ester, a fluorescence precursor sensing intracellular hydroperoxide generation. Livers undergoing the 16-hour cold storage displayed an impaired recovery of bile acid-dependent bile output concurrent with a marked increase in hydroperoxide generation in hepatocytes, which occurred as early as 5 minutes after the onset of reperfusion, whereas the status of lobular perfusion was well maintained. Pretreatment with liposome-encapsulated dichloromethylene diphosphonate, a Kupffer cell-depleting reagent, did neither alter the reperfusion-induced periportal oxidative changes nor improve the recovery of bile output in the graft. On the other hand, EPCK, a hepatotropic antioxidant composed of vitamin E phosphate ester bound to vitamin C, not only diminished the oxidative changes but also improved the reduction of bile acid-dependent bile output. Furthermore, the reagent was capable of inhibiting H2O2-induced oxidative stress in cultured hepatocytes. These results suggest that hepatocytes constitute a major site of the oxidative insult triggered through Kupffer cell-independent mechanisms and serve as an important cellular component to be protected by antioxidant therapeutics.