Investigation of hibernation marker and energy metabolism relating substances in the brain and brown fat.

通过对金黄地鼠冬眠前后的生理变化进行研究，发现棕色脂肪组织（BAT）中解偶联蛋白1（UCP1）mRNA的表达水平在冬眠期间没有变化，但高于夏季动物。我们证实了基因表达在深度冬眠期间在主要器官中没有新的表现，如心脏，大脑，肝脏，包括BAT。因此，深冬眠动物UCP1 mRNA水平的增加可能是由于唤醒间歇期UCP1 mRNA的产生增加所致，BAT产热与BAT的血液供应控制是同步的。说明内皮型一氧化氮合成酶在BAT的血供机制中起重要作用，BAT的产热不仅受冷应激的影响，而且受制动应激的影响。反复施加制动应激可使大鼠产生适应性反应，产热功能增强。在产热增强过程中，UCP1基因表达受到调节。连续的活体测量表明，在从冬眠中醒来时，由于血流量突然增加，大脑可能会受到短暂的高水平氧化应激，这表明存在抗氧化防御功能。为了用于遥测与能量代谢有关的物质，我们研制了涂有含酶聚合物的细丝电极。然而，电极对大脑中物质的敏感性随着冬眠期间温度的降低而降低。因此，我们使用该电极对采用微透析方法从脑中采集的样品进行离体测量，并获得了良好的结果。

A series of studies was carried out to investigate the physiological changes that could be an indicator for entrance and exit of the hibernation.The level of mRNA of uncoupling protein 1(UCP1 mRNA) in the brown adipose tissue (BAT), a key protein to be served as a energy balance regulator through heat production, was not changed during hibernation period in hamsters, though was in higher level compared with summer animals. We confirmed that gene expression was not newly performed during deep hibernation in the major organs, such as the heart, brain, liver, including BAT. Therefore the increased UCP1 mRNA level in deep hibernating animals is considered to be due to the enhanced production during inter-bout arousal cenothermia.BAT thermogenesis is well synchronized with control of blood supply to BAT. We clarified that endothelium type nitric oxide synthetase plays an important role in the mechanism of blood supply to BAT.BAT heat production is augmented not only by chill stress but by immobilization stress. If the immobilization stress is added repetitively in rats, adaptation will take place and thermogenic function is enhanced. In the thermogenesis enhancement, modulation of UCP1 gene expression was involved.Continuous in vivo measurement revealed that at the time of awakening from hibernation, the brain would be possibly exposed to transient oxidization stress of high level due to sudden increase in blood flow, and that is suggesting that existence of an anti-oxidization defense function.To use in telemetry of the substances relating to energy metabolism, we developed fine-wire electrode coated with enzyme containing polymer However, the sensitivity of electrode to substances in the brain was decreased concomitantly with temperature decreases during hibernation. Therefore, we used the electrode for ex vivo measurements of the samples collected from the brain by using microdialysis method, and got good results.