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

我们进行了一系列的研究，以探讨冬眠进入和退出的生理变化。褐脂肪组织（BAT）中解偶联蛋白1（UCP1 mRNA）是一种通过产热来调节能量平衡的关键蛋白，其mRNA水平在仓鼠冬眠期间没有变化，但高于夏季动物。我们证实，在包括BAT在内的心脏、大脑、肝脏等主要器官的深度冬眠中，基因表达并不是新的。因此，深冬眠动物中UCP1 mRNA水平的升高被认为是由于回合间唤醒体温时产生的增强。BAT产热与控制BAT的血供同步。研究表明，内皮型一氧化氮合成酶在bat的血供机制中起重要作用，bat的产热不仅受到冷应激的影响，还受到固定应激的影响。如果在大鼠体内反复施加固定应激，会使大鼠产生适应性，使其产热功能增强。在产热增强中，参与了UCP1基因表达的调节。体内连续测量表明，在冬眠醒来时，由于血流量的突然增加，大脑可能会受到高水平的瞬时氧化应激，这表明大脑存在抗氧化防御功能。为了对与能量代谢有关的物质进行遥测，我们研制了含酶聚合物包覆的细丝电极，但在冬眠过程中，电极对脑内物质的敏感性随着温度的降低而降低。因此，我们利用该电极对微透析法采集的大脑样本进行离体测量，取得了良好的结果。

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.