Hemolysis is a primary ATP-release mechanism in human erythrocytes
Hemolysis is a primary ATP-release mechanism in human erythrocytes
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DOI：
10.1182/blood-2014-05-572024
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发表时间：
2014-09-25
期刊：
影响因子：
20.3
通讯作者：
Grygorczyk, Ryszard
中科院分区：
文献类型：
--
作者：
Sikora, Jacek;Orlov, Sergei N.;Grygorczyk, Ryszard
红细胞ATP释放的调节机制是一氧化氮依赖性调节局部血流的重要机制，这一假说引起了人们对ATP释放机制的极大兴趣。一些刺激，包括剪切应力和缺氧，已被发现诱导显着的红细胞ATP释放归因于ATP传导通道的激活。在本研究中，我们首先评估了研究刺激的红细胞ATP释放和量化溶血的不同实验方法。然后，我们测量了每个RBC上清液样品中的ATP和游离血红蛋白，以直接评估溶血对ATP释放的贡献。低渗休克，剪切应力，缺氧，而不是环磷酸腺苷激动剂，显着增强ATP的释放。然而，它与RBC上清液中的游离血红蛋白密切相关，表明溶解是大多数（如果不是全部）ATP释放的原因。荧光ATP成像结合同时红外细胞成像显示，ATP完全从裂解细胞释放，没有完整细胞的贡献。总之，在测试的所有刺激物中，我们没有发现除了细胞裂解以外，完整RBC中ATP释放受调节的证据。这种释放机制可能与体内生理相关，例如，在运动和缺氧期间，血管内溶血（主要是衰老细胞）增加。
The hypothesis that regulated ATP release from red blood cells (RBCs) contributes to nitric oxide-dependent control of local blood flow has sparked much interest in underlying release mechanisms. Several stimuli, including shear stress and hypoxia, have been found to induce significant RBC ATP release attributed to activation of ATP-conducting channels. In the present study, we first evaluated different experimental approaches investigating stimulated RBC ATP release and quantifying hemolysis. We then measured ATP and free hemoglobin in each and every RBC supernatant sample to directly assess the contribution of hemolysis to ATP release. Hypotonic shock, shear stress, and hypoxia, but not cyclic adenosine monophosphate agonists, significantly enhanced ATP release. It tightly correlated, however, with free hemoglobin in RBC supernatants, indicating that lysis was responsible for most, if not all, ATP release. Luminescence ATP imaging combined with simultaneous infrared cell imaging showed that ATP was released exclusively from lysing cells with no contribution from intact cells. In summary, with all stimuli tested, we found no evidence of regulated ATP release from intact RBCs other than by cell lysis. Such a release mechanism might be physiologically relevant in vivo, eg, during exercise and hypoxia where intravascular hemolysis, predominantly of senescent cells, is augmented.