Measurement of endogenous anti-oxidants by non-restraint continuous measuring device: evaluation of its possibility as the hibernation marker.

采用体温非依赖测量系统，测定了叙利亚仓鼠在冬眠过程中脑内内源性水溶性抗氧化剂的含量。此外，在冬眠状态下(体温约6℃)，利用放射性和非放射性同位素，通过微量探针将代谢底物(葡萄糖和乳酸)注入金黄地鼠脑内，利用高效液相色谱法和核磁共振技术对代谢产物进行示踪。此外，通过股静脉慢性导管注射同位素标记的葡萄糖，并进行类似的测量。1)在整个冬眠过程中，血糖水平保持在相对稳定的水平，而标记的血糖水平随着时间的推移而下降。2)脑组织中抗坏血酸、谷胱甘肽含量不变，尿酸下降到1/2~1/3。3)脑ECF中：冬眠动物的抗坏血酸水平高于清醒动物，并随冬眠时间的延长而降低。尿酸水平除了在冬眠的觉醒阶段短暂升高外，没有改变。谷胱甘肽水平随温度变化呈正相关。4)阻断嘌呤核苷酸对尿酸的代谢，抑制尿酸的短暂升高和抗坏血酸的降低。这些结果表明，冬眠期间血糖水平保持良好，抗坏血酸对冬眠唤醒时推测的氧化应激起到了对抗作用。5)虽然深冬眠时脑组织匀浆中的谷氨酰胺、谷氨酸和GABA增加，但在脑内皮细胞中检测不到这些。神经元和星形胶质细胞之间的谷氨酰胺-谷氨酸循环在冬眠时似乎不起作用。这些发现可能有助于预测冬眠的开始作为一个标志。

By using body-temperature-independent measuring system, endogenous water-soluble anti-oxidant in the Syrian hamster brain was measured along the time course of hibernation. Moreover, the metabolic products were traced by administering a metabolic substrate (glucose and lactic acid) through the microdialisys probe to the hamster brain under hibernation (body temperature about 6℃) with the radioactive and the non-radioactive isotope, by means of using HPLC and the nuclear magnetic resonance (NMR) method. In addition, the isotope-labeled glucose was injected through the chronic femoral vein catheter, and a similar measurement was done. 1) Blood glucose level was relatively well maintained constant throughout the hibernation, while the labeled glucose decreased as time goes by. 2) Brain tissue level of the antioxidant (ascorbic acid, glutathione) was invariable but uric acid decreased to 1/2-1/3. 3) In the brain ECF: ascorbic acid level was higher in the hibernating animals than in the awaking animals, and decreased along the time course of arousing from hibernation. The uric acid level did not change except for a transient elevation during arousal phase of hibernation. Glutathione level showed temperature dependent changes in positive correlation. 4) Blockade of the purine nucleotide metabolism to the uric acid inhibited both the transient increase of uric acid and decrease of ascorbic acid.These results suggested that blood glucose level is well maintained during hibernation, and the ascorbic acid functioned against the oxidation stress guessed during arousal from hibernation.5) Though the glutamine, the glutamic acid, and GABA in the brain tissue homogenate increased during deep hibernation, these were not detected in the brain ECF.The glutamine-glutamate cycle between the neurons and the astrocytes seems not to be functional while hibernating. These findings may be useful to forecast the beginning of hibernation as a marker.