The relationship of oxygen delivery to absolute haemoglobin oxygenation and mitochondrial cytochrome oxidase redox state in the adult brain: a near-infrared spectroscopy study
The relationship of oxygen delivery to absolute haemoglobin oxygenation and mitochondrial cytochrome oxidase redox state in the adult brain: a near-infrared spectroscopy study
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DOI：
10.1042/bj3320627
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发表时间：
1998-06-15
影响因子：
4.1
通讯作者：
Nemoto, EM
中科院分区：
文献类型：
--
作者：
Cooper, CE;Delpy, DT;Nemoto, EM
用近红外光谱分析方法研究了成年大鼠脑供氧速率的变化对线粒体细胞色素氧化酶中氧合血红蛋白和脱氧血红蛋白的绝对浓度及铜(A)中心的氧化还原状态的影响。细胞色素氧化酶检测算法被确定为对血红蛋白氧合和浓度的大变化具有很强的健壮性。在假设100%N(2O)O机械通气后血红蛋白完全脱氧和铜(A)还原的条件下，计算了正常成人脑内氧合血红蛋白(35 MU M)、脱氧血红蛋白(27 MU M)的绝对浓度和铜(A)的氧化还原状态(82%氧化)。平均动脉压通过放血降低。当压力达到100毫米汞柱时，血红蛋白氧合作用开始下降，但只有当脑血容量自动调节机制在50毫米汞时失效时，总血红蛋白浓度和氧化铜(A)水平才会下降。随着向大脑输送氧气的速率的降低，血红蛋白的含氧量呈线性下降，但氧化的铜(A)浓度直到这个速率达到正常的50%时才开始下降。结果表明，大脑维持着足够的氧气输送到线粒体，近红外光谱可能是体内氧气不足的一个很好的衡量标准。
Near-infrared spectroscopy was used to determine the effect of changes in the rate of oxygen delivery to the adult rat brain on the absolute concentrations of oxyhaemoglobin, deoxyhaemoglobin and the redox state of the Cu(A) centre in mitochondrial cytochrome oxidase. The cytochrome oxidase detection algorithm was determined to be robust to large changes in haemoglobin oxygenation and concentration. By assuming complete haemoglobin deoxygenation and Cu(A) reduction following mechanical ventilation on 100% N(2)O, the absolute concentration of oxyhaemoglobin (35 mu M), deoxyhaemoglobin (27 mu M) and the redox state of Cu(A) (82% oxidized) were calculated in the normal adult brain. The mean arterial blood pressure was decreased by exsanguination. When the pressure reached 100 mmHg, haemoglobin oxygenation started to fall, but the total haemoglobin concentration and oxidized Cu(A) levels only fell when cerebral blood volume autoregulation mechanisms failed at 50 mmHg. Haemoglobin oxygenation fell linearly with decreases in the rate of oxygen delivery to the brain, but the oxidized Cu(A) concentration did not start to fall until this rate was 50% of normal. The results suggest that the brain maintains more than adequate oxygen delivery to mitochondria and that near-infrared spectroscopy may be a good measure of oxygen insufficiency in vivo.