ATP-dependent efflux of GSSG and GS-conjugate from isolated rat hepatocytes.
ATP-dependent efflux of GSSG and GS-conjugate from isolated rat hepatocytes.
复制标题
GSSG 和 GS 结合物从离体大鼠肝细胞中的 ATP 依赖性流出。
DOI：
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发表时间：
1990
影响因子：
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通讯作者：
P. Jansen
中科院分区：
文献类型：
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作者：
R. Elferink;R. Ottenhoff;W. Liefting;B. Schoemaker;A. Groen;P. Jansen
本文研究了二硝基苯基谷胱甘肽（GS-DNP）和氧化型谷胱甘肽（GSSG）从新鲜分离的大鼠肝细胞外排的驱动力。在Krebs中孵育肝细胞，增加K+浓度（等同于Na+）或在Krebs中孵育3 mM哇巴因，导致质膜电位部分或完全消散，通过36 Cl-的平衡分布测定。这对GSSG和GS-DNP的初始外排率没有影响。另一方面，通过不同的独立机制部分耗尽细胞ATP含量显着降低了这些化合物的初始流出率。用不同浓度的甘草苷孵育细胞，滴定细胞ATP含量，发现细胞ATP含量与GS-DNP的初始外排速率之间呈线性关系。还在来自具有肝胆转运缺陷的突变大鼠（TR-大鼠）的肝细胞中研究了GS-DNP的外排。这些大鼠具有遗传性小管分泌缺陷的一些有机阴离子，包括GS-DNP。如我们先前所示，GS-DNP从TR-大鼠肝细胞的流出显著慢于从正常肝细胞的流出（J.Clin.Invest. 84：476-483，1989）。这些细胞中细胞ATP含量的耗尽对GS-DNP的残留流出没有显著影响。从这些研究中，我们得出结论，ATP依赖的运输系统的氧化型谷胱甘肽和谷胱甘肽共轭物参与这些化合物的胆汁转运。这种运输系统与其他细胞类型和组织，如红细胞和心脏肌膜中所描述的可能的关系进行了讨论。
The driving force for efflux of dinitrophenyl-glutathione (GS-DNP) and oxidized glutathione (GSSG) from freshly isolated rat hepatocytes was studied. Incubation of hepatocytes in Krebs with increasing K+ concentrations (equivalently replaced for Na+) or in Krebs with 3 mM ouabain led to a partial or complete dissipation of the plasma membrane potential, as measured by the equilibrium distribution of 36Cl-. This had no effect on the initial efflux rate of GSSG and GS-DNP. On the other hand, partial depletion of the cellular ATP content via different independent mechanisms significantly reduced the initial efflux rate of these compounds. Titration of the cellular ATP content by incubation of the cells with different concentrations of atractyloside revealed a linear relation between the cellular ATP content and the initial efflux rate of GS-DNP. The efflux of GS-DNP was also studied in hepatocytes from mutant rats with hepatobiliary transport defect (TR- rats). These rats have a hereditary canalicular secretion defect for a number of organic anions including GS-DNP. As we have shown previously, the efflux of GS-DNP from TR- rat hepatocytes is significantly slower than from normal hepatocytes (J. Clin. Invest. 84: 476-483, 1989). Depletion of the cellular ATP content in these cells had no significant effect on the residual efflux of GS-DNP. From these studies, we conclude that an ATP-dependent transport system for oxidized glutathione and glutathione conjugates is involved in the biliary transport of these compounds. The possible relation of this transport system with that described in other cell types and tissues, like erythrocytes and heart sarcolemma, is discussed.