Last Word on Viewpoint: Managing the power grid: how myoglobin can regulate Po2 and energy distribution in skeletal muscle.
Last Word on Viewpoint: Managing the power grid: how myoglobin can regulate Po2 and energy distribution in skeletal muscle.
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观点最后一句话：管理电网：肌红蛋白如何调节骨骼肌中的 Po2 和能量分布。
DOI：
10.1152/japplphysiol.00046.2019
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Clanton,ThomasL
中科院分区：
文献类型：
--
作者：
Clanton,ThomasL
感谢所有对此观点（见参考文献2）的回应者（见参考文献1）。这才是真正的快乐。博克和克鲁斯提出了甜菜根补充剂对运动对象的影响。我同意血管反应似乎是补充剂作用的更可能机制，因为大概有足够的肌肉硝酸盐储存来支持与肌红蛋白（Mb）的内源性反应。一个重要的问题是，在没有补充剂的情况下，从肌肉分泌的内源性硝酸盐是否可以促进与血管壁中的细胞珠蛋白的反应，以帮助血流调节。几位作者指出了可能有助于调节网格的其他机制。克里斯·唐纳利描述了糖原的局部分布如何促进肌膜附近的代谢。Alain Riveros-Rivera提出了温度对DO 2的影响。Dowd等人(3)模拟了温度效应，发现它们只能解释DO 2变化的一小部分，但值得注意的是，它们没有评估所有因素。Li Zuo描述了脱氧Mb在ROS产生中的作用。有趣的是，ROS也可以抑制低PO 2区域的呼吸。例如，超氧化物与细胞色素c快速反应，干扰上游电子流（6），局部H2 O2降低CcO活性（5）。CcO和Mb在膜间隙（8）内的接近将促进这些反应。丹尼尔平井及其同事提到了霍尼格和加耶斯基的工作，他们提供了一种运动升高DO 2的机制。他们显示出不成比例的减少PO 2肌膜下方，减少了有效的扩散距离O2。穿过这个狭窄间隙的扩散包括肌纤维O2通量中的“速率限制步骤”。通过Mb在促进扩散中的作用，使穿过纤维其余部分的O2梯度最小化。这里提出的模型增加了Honig和Gayeski论文的优雅性，因为该区域Vo 2的同时和不成比例的增加将进一步减少PO 2并驱动扩散。总之，这些想法支持Honig和Gayeski的原始概念的“招募储备O2扩散运输”的运动。
Thanks to all of the respondents (see Ref. 1) to this Viewpoint (see Ref. 2). This was a true joy. Bock and Kruse bring up the effects of beetroot supplements in exercising subjects. I agree that a vascular response seems a more likely mechanism for effects of supplements, because presumably there are sufficient muscle nitrate stores to support endogenous reactions with myoglobin (Mb). An important question is whether, in the absence of supplements, endogenous nitrate secreted from muscle could facilitate reactions with cytoglobin residing in the vascular wall to assist in blood flow regulation.Several authors point out additional mechanisms that could contribute to regulation of the grid. Chris Donnelly describes how local distributions of glycogen might facilitate metabolism close to the sarcolemma. Alain Riveros-Rivera brings up the effect of temperature on DO2. Dowd et al.(3) modeled temperature effects and found that they can only account for a small fraction of the change in DO2, but notably they did not evaluate all factors. Li Zuo describes a role for deoxygenated Mb in ROS production. Interestingly, ROS could also suppress respiration in areas of low PO2. For example, superoxide reacts rapidly with cytochrome c, interfering with upstream electron flow (6), and local H2O2 diminishes CcO activity (5). The proximity of CcO and Mb within the intermembrane space (8) would facilitate these reactions. Daniel Hirai and colleagues refer to the work of Honig and Gayeski who provided a mechanism for elevations in DO2 with exercise. They showed a disproportionate reduction in PO2 just below the sarcolemma, reducing the effective diffusion distance for O2. Diffusion across this narrow gap comprises the “rate limiting step” in myofiber O2 flux. O2 gradients across the rest of the fiber are minimized by Mb’s role in facilitated diffusion. The model proposed here adds to the elegance of Honig and Gayeski’s thesis, because simultaneous and disproportionate increases in Vo2 in this region would further reduce PO2 and drive diffusion. Together, these ideas support Honig and Gayeski’s original concept of the “recruited reserve for O2 diffusive transport” in exercise.
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观点评论：管理电网：肌红蛋白如何调节骨骼肌中的 Po2 和能量分布。
影响因子：
3.3
作者：
J. Bock;N. Kruse;C. Donnelly;D. Hirai;J. Craig;Trenton D. Colburn;T. Musch;D. Poole;R. Rosenberry;Fenghua Tian;Hanli Liu;M. Nelson;B. Piknova;W. Willis;L. Zuo;Tingyang Zhou;A. Riveros;E. Cristancho;H. Gunga
通讯作者：
H. Gunga
影响因子：
8.8
作者：
Glancy B;Hartnell LM;Combs CA;Femnou A;Sun J;Murphy E;Subramaniam S;Balaban RS
通讯作者：
Balaban RS
使用 HPLC 测量活检大小的肌肉样品中的硝酸盐和亚硝酸盐。
DOI：
10.1152/japplphysiol.00625.2018
发表时间：
2018
期刊：
Journal of applied physiology (Bethesda, Md. : 1985)
影响因子：
--
作者：
Troutman,AshleyD;Gallardo,EdgarJ;Brown,MaryBeth;Coggan,AndrewR
通讯作者：
Coggan,AndrewR
温度对骨骼肌中肌红蛋白促进的氧运输的影响。
影响因子：
3.4
作者：
M. Dowd;R. Murali;R. Seagrave
通讯作者：
R. Seagrave