Nemoto E M, Yao L, Yonas H, Darby J M
Department of Anesthesiology/CCM, University of Pittsburgh School of Medicine, Pennsylvania 15261.
J Neurosurg Anesthesiol. 1994 Jul;6(3):170-4. doi: 10.1097/00008506-199407000-00004.
The cerebral metabolic rate of oxygen (CMRO2) has been functionally compartmentalized using the barbiturate thiopental into active CMRO2, associated with electroencephalographic (EEG) activity, and the balance, basal CMRO2, associated with the maintenance of neuronal viability. Previous measurements of these CMRO2 compartments were made in anesthetized animals. Our aim was to determine whether the same proportions for these compartments applied in unanesthetized monkeys. The active: basal distribution of the cerebral metabolic rate of glucose (CMRG) and cerebral flood flow (CBF) were also determined. Three measurements of whole-brain CBF (H2 clearance), CMRO2, and CMRG were made in six unanesthetized rhesus monkeys (Macaca mulatta). Thereafter, thiopental anesthesia was induced and maintained until an isoelectric EEG was obtained. Three additional measurements of CBF, CMRO2, and CMRG were made. Arterial blood pressure, end-tidal CO2, and arterial blood gas were measured with each set of measurements. Thiopental-induced isoelectric EEG resulted in a 47% reduction in CMRO2 from 5.95 +/- 0.54 to 3.10 +/- 0.51 ml/100 g/min (mean +/- SD); a 36% reduction in CBF from 76 +/- 21 to 48 +/- 14 ml/100 g/min; and a 61% reduction in CMRG from 8.09 +/- 2.78 to 3.13 +/- 0.77 mg/100 g/min. The oxygen-glucose index was 0.99 +/- 0.10 for the whole brain, 0.87 +/- 0.15 for the active, and 1.27 +/- 0.25 for the basal compartments. These results indicated an active:basal distribution of approximately 50:50 for CMRO2, 40:60 for CBF, and 60:40 for CMRG. The active:basal CMRO2 distribution corroborates earlier data and shows that relative to CMRO2, the active compartment is underperfused with a lower oxygen-glucose index compared with the basal compartment.
利用巴比妥类药物硫喷妥钠，可将脑氧代谢率（CMRO2）在功能上划分为与脑电图（EEG）活动相关的活性CMRO2，以及与神经元活力维持相关的剩余部分，即基础CMRO2。以往对这些CMRO2区室的测量是在麻醉动物身上进行的。我们的目的是确定这些区室的相同比例是否适用于未麻醉的猴子。同时还测定了脑葡萄糖代谢率（CMRG）和脑血流量（CBF）的活性：基础分布。对6只未麻醉的恒河猴（猕猴）进行了全脑CBF（H2清除率）、CMRO2和CMRG的三次测量。此后，诱导并维持硫喷妥钠麻醉，直至获得等电位脑电图。又进行了CBF、CMRO2和CMRG的三次测量。每次测量时均测量动脉血压、呼气末二氧化碳和动脉血气。硫喷妥钠诱导的等电位脑电图导致CMRO2从5.95±0.54降至3.10±0.51 ml/100 g/min（平均值±标准差），降低了47%；CBF从76±21降至48±14 ml/100 g/min，降低了36%；CMRG从8.09±2.78降至3.13±0.77 mg/100 g/min，降低了61%。全脑的氧-葡萄糖指数为0.99±0.10，活性区室为0.87±0.15，基础区室为1.27±0.25。这些结果表明，CMRO2的活性：基础分布约为50:50，CBF为40:60，CMRG为60:40。活性：基础CMRO2分布证实了早期数据，并表明相对于CMRO2，活性区室灌注不足，与基础区室相比，氧-葡萄糖指数较低。
