Darriet D, Der T, Collins R C
J Cereb Blood Flow Metab. 1986 Feb;6(1):8-14. doi: 10.1038/jcbfm.1986.2.
Studies in experimental animals and post-mortem studies in humans have indicated that the level of the mitochondrial enzyme cytochrome oxidase within brain anatomical pathways is regulated by the long-term functional use of those pathways. To study this relationship, we have measured cytochrome oxidase spectrophotometrically in punch biopsies from different brain regions of rat. We compared these assays against results from the diaminobenzidine histochemical technique. We found a high degree of correlation (r = 0.90) between the density of diaminobenzidine reaction product and enzyme activity. This validates the usefulness of the diaminobenzidine technique for anatomical localization and measurement of this enzyme. To study the feasibility of using radioactive cyanide as an in vivo ligand of cytochrome oxidase, we performed quantitative autoradiographic analysis of rat brains of animals given an intravenous bolus injection of [14C]cyanide. Analysis of the arterial blood curve indicated a complex redistribution of cyanide between red blood cells, plasma, and tissues. Brain labeling reached peak levels at 1 min and then fell despite rising concentrations of free plasma cyanide. Analysis of autoradiographic images revealed good anatomical resolution. The density of labeling in individual structures over time failed to show a strong correlation with cytochrome oxidase activity or diaminobenzidine reaction product.
对实验动物的研究以及对人类的尸检研究表明，脑解剖通路中线粒体酶细胞色素氧化酶的水平受这些通路长期功能使用情况的调节。为了研究这种关系，我们用分光光度法测量了大鼠不同脑区打孔活检组织中的细胞色素氧化酶。我们将这些测定结果与二氨基联苯胺组织化学技术的结果进行了比较。我们发现二氨基联苯胺反应产物的密度与酶活性之间存在高度相关性（r = 0.90）。这证实了二氨基联苯胺技术在该酶的解剖定位和测量方面的有用性。为了研究使用放射性氰化物作为细胞色素氧化酶体内配体的可行性，我们对静脉推注[14C]氰化物的动物的大鼠脑进行了定量放射自显影分析。对动脉血曲线的分析表明，氰化物在红细胞、血浆和组织之间进行复杂的重新分布。尽管游离血浆氰化物浓度不断升高，但脑标记在1分钟时达到峰值水平，然后下降。对放射自显影图像的分析显示出良好的解剖分辨率。随着时间的推移，各个结构中的标记密度与细胞色素氧化酶活性或二氨基联苯胺反应产物之间未显示出强烈的相关性。
