Ferrari M, Hanley D F, Wilson D A, Traystman R J
Department of Anesthesiology/Critical Care Medicine, Johns Hopkins Medical Institutions, Baltimore, Maryland 21205.
Am J Physiol. 1990 Jun;258(6 Pt 2):H1706-13. doi: 10.1152/ajpheart.1990.258.6.H1706.
Rapid scanning near-infrared spectroscopy (730-960 nm) was utilized to determine cat brain cytochrome-c oxidase copper band by blood-perfluorochemical emulsion (Oxypherol) exchange. Spectra were carried out before, during, and after the exchange transfusion on animals with preserved somatosensory-evoked potentials and microsphere-determined cerebral blood flow. Remaining hemoglobin (less than 4% of control) was converted to carboxyhemoglobin that does not absorb in this spectral region. Difference spectra, between an hypercapnic status (8% CO2-92% O2) and postmortem, demonstrated the presence of a broad absorption band centered around 820-845 nm that could be attributed to the oxidized low potential copper ion (CuA) of cytochrome-c oxidase. However, we were unable to further oxidize this band by adding CO2 to the inspired gas mixture, but this inconsistency may be due to the near-maximal cerebral blood flow levels present in this preparation. Cytochrome oxidation by CO2 is normally attributed to increased O2 delivery to the tissue, secondary to an increased cerebral perfusion. We were unable to induce further increases in cerebral blood flow. In contrast, the cytochrome band could be reduced both by lowering fractional O2 concentration and by inducing circulatory arrest. The spectral data support the hypothesis that it is possible to quantify the cytochrome-c oxidase copper band in the near-infrared spectral region.
利用快速扫描近红外光谱法（730 - 960纳米），通过血液全氟化学乳剂（Oxypherol）交换来测定猫脑细胞色素c氧化酶铜带。对保留体感诱发电位和微球测定脑血流量的动物，在交换输血前、输血过程中和输血后进行光谱测定。剩余血红蛋白（小于对照的4%）转化为在此光谱区域不吸收的碳氧血红蛋白。高碳酸血症状态（8%二氧化碳 - 92%氧气）与死后状态之间的差异光谱显示，存在一个以820 - 845纳米为中心的宽吸收带，这可归因于细胞色素c氧化酶的氧化态低电位铜离子（CuA）。然而，我们无法通过向吸入气体混合物中添加二氧化碳来进一步氧化该吸收带，但这种不一致可能是由于该制剂中存在接近最大的脑血流量水平。二氧化碳引起的细胞色素氧化通常归因于脑灌注增加导致组织获得的氧气输送增加。我们无法诱导脑血流量进一步增加。相反，通过降低氧气分数浓度和诱导循环停止，细胞色素带均可被还原。光谱数据支持这样一种假设，即在近红外光谱区域对细胞色素c氧化酶铜带进行量化是可能的。
