Drew Clare, Ball Vicky, Robinson Hannah, Clive Ellory J, Gibson John S
University Laboratory of Physiology, Parks Road, Oxford OX1 3PT, UK.
Bioelectrochemistry. 2004 May;62(2):153-8. doi: 10.1016/j.bioelechem.2003.07.003.
In this paper, we provide an update on O2-dependent membrane transport in red cells. O2-sensitive membrane transport was compared in nucleated (chicken) and enucleated (human) red cells, to investigate effects on organic (glucose transporter [GLUT]) and inorganic (K(+)-Cl- cotransporter [KCC]/Na(+)-K(+)-2Cl- cotransporter [NKCC]) transporters, to study the response of so-called "housekeeping" transporters (Na+/K+ pump and anion exchanger [AE]) and, finally, to compare O2 sensitivity in normal human red cells with those from sickle cell patients. The Na+/K+ pump showed no change in activity between oxygenated and deoxygenated cells in any of the samples. KCC in normal human red cells had the greatest O2 sensitivity, being stimulated some 20-fold on oxygenation. It was more modestly stimulated by O2 in chicken red cells and HbS cells. By contrast, NKCC was stimulated by deoxygenation in all cases. GLUT showed little response to O2 tension, other than a small stimulation in deoxygenated chicken red cells. Finally, AE1 was stimulated by oxygenation in HbA cells, but this stimulation by O2 was absent in HbS cells and pink ghosts prepared from HbA cells. The significance of these findings is discussed.
在本文中，我们提供了红细胞中氧依赖膜转运的最新情况。比较了有核（鸡）红细胞和无核（人）红细胞中对氧敏感的膜转运，以研究对有机（葡萄糖转运体[GLUT]）和无机（钾氯共转运体[KCC]/钠钾氯共转运体[NKCC]）转运体的影响，研究所谓“管家”转运体（钠钾泵和阴离子交换体[AE]）的反应，最后，比较正常人类红细胞与镰状细胞病患者红细胞的氧敏感性。在任何样本中，氧合和脱氧细胞之间钠钾泵的活性均无变化。正常人类红细胞中的KCC对氧的敏感性最高，氧合时其活性被刺激约20倍。在鸡红细胞和血红蛋白S（HbS）细胞中，其受氧的刺激作用较小。相比之下，在所有情况下，脱氧均会刺激NKCC。除了在脱氧鸡红细胞中有轻微刺激外，GLUT对氧张力几乎没有反应。最后，在血红蛋白A（HbA）细胞中，AE1受氧合刺激，但在HbS细胞和由HbA细胞制备的血影中，这种氧刺激不存在。讨论了这些发现的意义。
