Activation of endothelial NADPH oxidase during normoxic lung ischemia is KATP channel dependent.
Activation of endothelial NADPH oxidase during normoxic lung ischemia is KATP channel dependent.
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常氧肺缺血期间内皮 NADPH 氧化酶的激活是 KATP 通道依赖性的。
DOI：
10.1152/ajplung.00210.2005
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
Fisher,AronB
中科院分区：
文献类型：
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作者：
Zhang,Qunwei;Matsuzaki,Ikuo;Chatterjee,Shampa;Fisher,AronB
先前的研究表明，内皮细胞膜去极化和内皮细胞中活性氧（ROS）的产生，导致剪切应力突然降低（缺血）。本研究使用 Kir6.2−/− 和 gp91phox−/− 小鼠评估了 ATP 敏感钾 (KATP) 通道和 NADPH 氧化酶在缺血反应中的作用。为了评估 ROS 的产生，我们对用 2',7'-二氯二氢荧光素 (DCF)、氢乙啶 (HE) 或二苯基-1-芘基膦 (DPPP) 标记的分离的小鼠肺进行灌注，以控制灌注，然后进行全局缺血。在野生型 C57BL/6J 小鼠中，胸膜下内皮细胞成像显示，所有三种荧光探针在缺血时强度均呈时间依赖性增加，而预灌注 Cromakalim（一种 KATP 通道激动剂）或二亚苯基碘鎓（DPI，一种黄素蛋白抑制剂）可阻断这种强度。双氧杂菁（一种膜电位探针）的内皮细胞荧光在肺缺血期间增加，表明细胞膜去极化。 gp91phox−/−小鼠肺部缺血时膜电位的变化与野生型相似，但没有发生ROS生成。 Kir6.2−/− 的肺显示膜电位和 ROS 产生的变化显着减弱。因此，肺缺血期间的膜去极化需要 KATP 通道的存在，并且是 NADPH 氧化酶激活和内皮 ROS 生成所必需的。
Previous studies have shown endothelial cell membrane depolarization and generation of reactive oxygen species (ROS) in endothelial cells with abrupt reduction in shear stress (ischemia). This study evaluated the role of ATP-sensitive potassium (KATP) channels and NADPH oxidase in the ischemic response by using Kir6.2−/− and gp91phox−/− mice. To evaluate ROS generation, we subjected isolated perfused mouse lungs labeled with 2′,7′-dichlorodihydrofluorescein (DCF), hydroethidine (HE), or diphenyl-1-pyrenylphosphine (DPPP) to control perfusion followed by global ischemia. In wild-type C57BL/6J mice, imaging of subpleural endothelial cells showed a time-dependent increase in intensity for all three fluorescence probes with ischemia, which was blocked by preperfusion with cromakalim (a KATPchannel agonist) or diphenyleneiodonium (DPI, a flavoprotein inhibitor). Endothelial cell fluorescence with bis-oxonol, a membrane potential probe, increased during lung ischemia indicating cell membrane depolarization. The change in membrane potential with ischemia in lungs of gp91phox−/− mice was similar to wild type, but ROS generation did not occur. Lungs from Kir6.2−/− showed marked attenuation of the change in both membrane potential and ROS production. Thus membrane depolarization during lung ischemia requires the presence of a KATPchannel and is required for activation of NADPH oxidase and endothelial ROS generation.