Nomura Y, Matsunaga A, Tamura M
Biophysics Division, Hokkaido University, Sapporo, Japan.
J Neurosci Methods. 1998 Aug 1;82(2):135-44. doi: 10.1016/s0165-0270(98)00045-4.
For the precise examination of the optical characteristics of cerebral tissue, we prepared hemoglobin-free perfused rat heads, from which trace amounts of blood were completely removed. In this preparation at 30 degrees C, the redox responses of the cytochrome oxidase components, heme a + a3 and copper, were followed spectrophotometrically in visible and near-infrared regions, and were correlated with the changes in neural activity as monitored by electroencephalography (EEG). During the aerobic-anaerobic transition, there was clear dissociation of the time courses of the reduction of heme a + a3 and copper; the reduction of heme a + a3 preceded the reduction of copper. The EEG activity decreased earlier than the reduction of heme a + a3. Pentylenetetrazole administration in normoxia caused the partial reduction of heme a + a3 but not of copper. The redox behaviors of cytochrome oxidase components in the brain were identical to those observed in isolated mitochondria. The usefulness of brain preparation for bridging the in vivo and in vitro studies is documented where various circulatory parameters could be controlled artificially.
为了精确检测脑组织的光学特性，我们制备了无血红蛋白灌注大鼠头部，其中微量血液被完全清除。在30摄氏度的这种制备条件下，通过分光光度法在可见光和近红外区域跟踪细胞色素氧化酶成分血红素a + a3和铜的氧化还原反应，并将其与脑电图（EEG）监测的神经活动变化相关联。在有氧-无氧转变过程中，血红素a + a3和铜的还原时间进程明显分离；血红素a + a3的还原先于铜的还原。EEG活动比血红素a + a3的还原更早下降。在常氧条件下给予戊四氮导致血红素a + a3部分还原，但铜未还原。大脑中细胞色素氧化酶成分的氧化还原行为与在分离的线粒体中观察到的相同。记录了大脑制备在弥合体内和体外研究方面的有用性，其中各种循环参数可以人工控制。
