General redox environment and carotid body chemoreceptor function
General redox environment and carotid body chemoreceptor function
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DOI：
10.1152/ajpcell.00542.2008
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发表时间：
2009-03-01
影响因子：
5.5
通讯作者：
Obeso, Ana
中科院分区：
文献类型：
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作者：
Agapito, Maria Teresa;Sanz-Alfayate, Gloria;Obeso, Ana
Agapito MT，Sanz-Alfayate G，Gomez-Nino A，Gonzalez C，Obeso A。一般氧化还原环境和颈动脉体化学感受器功能。 Am J Physiol Cell Physiol 296：C620-C631，2009。首次发表于 2009 年 1 月 14 日； doi:10.1152/ajpcell.00542.2008.-颈动脉体 (CB) 化学感受器细胞检测缺氧的生理水平并产生过度通气，本质上是稳态，旨在最大限度地减少缺氧的有害影响。化学感受器细胞中参与氧传感的密切机制在很大程度上仍然未知，但活性氧（ROS）已被提议作为该过程的介质。我们测定了在两种类型的氧化剂存在下孵育的大鼠隔膜中的谷胱甘肽水平并计算了谷胱甘肽氧化还原电位（EGSH；细胞一般氧化还原环境的指标）：非渗透性和渗透性通过细胞膜；在后一组中，使用了非特异性氧化剂和 ROS 处理酶抑制剂。测试选定浓度的氧化剂改变化学感受器细胞的常氧和低氧活性的能力，在体外测量化学感受器细胞的神经递质释放速率。结果证明 EGSH 与化学感受器细胞活性之间存在可变关系。化学感受器细胞活性与 EGSH 的独立性意味着 CB 发挥其稳态作用的能力在引起氧化应激的任何病理或毒理学意外事件中很大程度上得以保留。与这一建议一致的是，还发现用显着降低所有分析组织中 EGSH 的药物治疗完整动物并没有改变 CB 介导的缺氧过度通气。
Agapito MT, Sanz-Alfayate G, Gomez-Nino A, Gonzalez C, Obeso A. General redox environment and carotid body chemoreceptor function. Am J Physiol Cell Physiol 296: C620-C631, 2009. First published January 14, 2009; doi:10.1152/ajpcell.00542.2008.-Carotid body (CB) chemoreceptor cells detect physiological levels of hypoxia and generate a hyperventilation, homeostatic in nature, aimed to minimize the deleterious effects of hypoxia. Intimate mechanisms involved in oxygen sensing in chemoreceptor cells remain largely unknown, but reactive oxygen species (ROS) had been proposed as mediators of this process. We have determined glutathione levels and calculated glutathione redox potential (EGSH; indicator of the general redox environment of cells) in rat diaphragms incubated in the presence of oxidizing agents of two types: nonpermeating and permeating through cell membranes; in the latter group, unspecific oxidants and inhibitors of ROS-disposing enzymes were used. Selected concentrations of oxidizing agents were tested for their ability to modify the normoxic and hypoxic activity of chemoreceptor cells measured in vitro as their rate of release of neurotransmitters. Results evidence variable relationships between EGSH and the activity of chemoreceptor cells. The independence of chemoreceptor cell activity from the EGSH would imply that the ability of the CB to play its homeostatic role is largely preserved in any pathological or toxicological contingency causing oxidative stress. Consistent with this suggestion, it was also found that CB-mediated hypoxic hyperventilation was not altered by treatment of intact animals with agents that markedly decreased the EGSH in all tissues assayed.