Does the Redox State of Cytochrome aa3 Reflect Brain Energy Level During Hypoxia? Simultaneous Measurements by Near Infrared Spectrophotometry and31 P Nuclear Magnetic Resonance Spectroscopy
Does the Redox State of Cytochrome aa3 Reflect Brain Energy Level During Hypoxia? Simultaneous Measurements by Near Infrared Spectrophotometry and31 P Nuclear Magnetic Resonance Spectroscopy
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细胞色素 aa3 的氧化还原状态是否反映缺氧期间大脑的能量水平？
DOI：
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发表时间：
1996
影响因子：
5.7
通讯作者：
N. Yoshimura
中科院分区：
文献类型：
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作者：
Hiromi Matsumoto;T. Oda;M. Hossain;N. Yoshimura
我们研究了缺氧时的脑氧代谢，以证明是否细胞色素aa 3（cyt.aa3）的氧化还原状态，通过近红外分光光度法（NIRS）测量，反映大脑的能量水平。用近红外光谱（NIRS）和~（31）P核磁共振波谱（NMRS）同步监测6只缺氧大鼠的脑组织。采用脑电图（EEG）评价脑功能。在吸入氧分数（FIO 2）从0.21降至0.15后，我们观察到减少的cyt.aa3显著增加（从16.5% +/- 2.1%至41.2% +/- 2.8%; P < 0.01），磷酸肌酸（PCr）和β-三磷酸腺苷（β-ATP）水平无显著变化。在FIO 2为0.10时，PCr显著降低（53.8% +/- 6.4%，而FIO（2）为0.21时为97.7% +/- 10.9%; P < 0.05），并在FIO 2为0.04时达到最小值。在FIO 2为0.10或0.08时，β-ATP没有显著变化。当FIO 2小于0.08时，cyt.aa3几乎完全减少。EEG活动在FIO 2为0.08时减慢，在0.04时变为等电位。在FIO（2）水平0 ~ 1.0范围内，cyt.aa3水平与PCr（P < 0.001，r = 0.83）及β-ATP（P < 0.001，r = 0.73）之间存在显著相关性。然而，当FIO 2小于0.10时，这些变量之间没有观察到显著相关性。这些研究结果表明，减少cyt.aa3的增加反映了脑能量消耗，但是，cyt.aa3的氧化还原状态不会表明在极端缺氧脑能量消耗，因为cyt.aa3是完全减少缺氧期间不足以耗尽细胞内ATP。（Anesth Analg 1996;83：513-8）
We studied cerebral oxygen metabolism during hypoxia to demonstrate whether the redox state of cytochrome aa3 (cyt.aa3), as measured by near infrared spectrophotometry (NIRS), reflects brain energy level. Rats (n = 6) subjected to hypoxia were simultaneously monitored by NIRS and31 P nuclear magnetic resonance spectroscopy (NMRS). Brain function was evaluated using the electroencephalogram (EEG). After a reduction of the fraction of inspired oxygen (FIO2) from 0.21 to 0.15, we observed a significant increase in reduced cyt.aa3 (from 16.5% +/- 2.1% to 41.2% +/- 2.8%; P < 0.01), without significant changes in phosphocreatine (PCr) and beta-adenosine triphosphate (beta-ATP) levels. The PCr decreased significantly at a FIO2 of 0.10 (53.8% +/- 6.4% as compared with 97.7% +/- 10.9% at a FIO (2) of 0.21; P < 0.05), and reached a minimum at a FIO2 of 0.04. beta-ATP did not change significantly at a FIO2 of 0.10 or 0.08. With a FIO2 of less than 0.08, cyt.aa3 was almost totally reduced. EEG activity slowed at a FIO2 of 0.08 and became isoelectric at 0.04. Significant correlations were found between the levels of cyt.aa3 and PCr (P < 0.001, r = 0.83) as well as between cyt.aa3 and beta-ATP (P < 0.001, r = 0.73) by using the overall values at FIO (2) levels from 0 to 1.0. However, no significant correlations were observed among these variables when the FIO2 was less than 0.10. These findings suggest that the increase in reduced cyt.aa3 reflects brain energy depletion; however, the redox state of cyt.aa3 will not indicate brain energy depletion during extreme hypoxia because cyt.aa3 is reduced totally during hypoxia insufficient to deplete intracellular ATP. (Anesth Analg 1996;83:513-8)
DOI：
10.1152/jappl.1990.68.6.2527
发表时间：
1990
期刊：
Journal of applied physiology (Bethesda, Md. : 1985)
影响因子：
--
作者：
Nioka,S;Smith,DS;Chance,B;Subramanian,HV;Butler,S;Katzenberg,M
通讯作者：
Katzenberg,M