Department of Medicine, VA Medical Center and University of Minnesota, 1 Veteran's Drive, Minneapolis, MN 55417, USA.
Respir Physiol Neurobiol. 2010 Dec 31;174(3):182-91. doi: 10.1016/j.resp.2010.08.015. Epub 2010 Aug 27.
The specialized oxygen-sensing tissues include the carotid body and arterial smooth muscle cells in the pulmonary artery (PA) and ductus arteriosus (DA). We discuss the evidence that changes in oxygen tension are sensed through changes in redox status. "Redox" changes imply the giving or accepting of electrons. This might occur through the direct tunneling of electrons from mitochondria or redox couples to an effector protein (e.g. ion channel). Alternatively, the electron might be transferred through reactive oxygen species from mitochondria or an NADPH oxidase isoform. The PA's response to hypoxia and DA's response to normoxia result from reduction or oxidation, respectively. These opposing redox stimuli lead to K+ channel inhibition, membrane depolarization and an increase in cytosolic calcium and/or calcium sensitization that causes contraction. In the neuroendocrine cells (the type 1 cell of the carotid body, neuroepithelial body and adrenomedullary cells), the response is secretion. We examine the roles played by superoxide anion, hydrogen peroxide and the anti-oxidant enzymes in the signaling of oxygen tensions.
专门的氧气感应组织包括颈动脉体和肺动脉（PA）和动脉导管（DA）中的动脉平滑肌细胞。我们讨论了氧张力变化是通过氧化还原状态的变化来感知的证据。“氧化还原”变化意味着电子的给予或接受。这可能通过电子从线粒体或氧化还原偶联物直接隧穿到效应蛋白（例如离子通道）来发生。或者，电子可能通过来自线粒体或 NADPH 氧化酶同工型的活性氧转移。PA 对缺氧的反应和 DA 对正常氧的反应分别来自还原或氧化。这些相反的氧化还原刺激导致 K+通道抑制、膜去极化以及细胞溶质钙增加和/或钙敏化，从而导致收缩。在神经内分泌细胞（颈动脉体的 1 型细胞、神经上皮体和肾上腺髓质细胞）中，反应是分泌。我们研究了超氧阴离子、过氧化氢和抗氧化酶在氧张力信号转导中的作用。
