布氏田鼠在冷暴露条件下褐色脂肪组织产热的神经内分泌调节  

Neuroendocrine regulation of thermogenesis of brown adipose tissue in the cold-exposed Brandt’s voles

作　　者：杨明[1] 李庆芬[1] 黄晨西[1] 

机构地区：[1]北京师范大学生物多样性与生态工程教育部重点实验室

出　　处：《动物学报》2003年第6期748-754,共7页ACTA ZOOLOGICA SINICA

基　　金：国家自然科学基金资助项目 (No .3 9970 12 4)~~

摘　　要：为了解野生小哺乳动物在冷暴露条件下褐色脂肪组织产热的调节机理 ,雄性布氏田鼠随机分为常温对照组 ( 2 4± 2℃ ,12L∶12D) ,冷暴露 1天、 1周和 4周组 ( 4± 1℃ ,12L∶12D ,分别处理 1天、 1周和 4周 ) ,驯化处理结束后测定下丘脑—垂体—甲状腺 (HPT)轴和下丘脑 -垂体 -肾上腺 (HPA)轴的中枢和外周激素及血清去甲肾上腺素含量。结果表明 :( 1) ,冷暴露布氏田鼠HPT轴持续处于激活状态 ,急性冷暴露下 ,由于下丘脑促甲状腺激素释放激素 (TRH)释放的增加而导致下丘脑TRH含量明显降低 ;慢性冷暴露后 ,下丘脑TRH的合成和经正中隆起 (ME)的释放显著增加 ,血清T3 水平随着冷暴露时间的延长而增加 ;( 2 )冷暴露持续激活布氏田鼠交感神经系统 ;( 3)急性冷暴露对布氏田鼠HPA轴的激活不明显 ,慢性冷暴露布氏田鼠HPA轴明显被激活 ,正中隆起促肾上腺皮质激素释放激素 (CRH)及血清皮质酮水平均增加 ,这可能是交感神经系统作用的结果 ;( 4 )下丘脑精氨酸加压素 (AVP)含量在冷暴露过程中变化不明显。冷暴露布氏田鼠的产热受到甲状腺激素、肾上腺皮质激素。This paper focuses on the regulation of hypothalamic pituitary thyroid (HPT) axis, hypothalamic pituitary adrenal (HPA) axis and sympathetic nervous system (SNS) on thermogenesis of brown adipose tissue (BAT) in Brandt’s voles ( Microtus brandti ). Male adult voles were divided into 4 groups, animals of regular temperature control group were kept in 24±2 ℃, 12L∶12D, while animals of cold groups were exposed to cold (4±1 ℃, 12L∶12D) for 1 day, 1 week and 4 weeks respectively. When voles were put into acute cold (1 day), GTP binding to BAT mitochondria increased while content of TRH in hypothalamus decreased markedly and concentrations of T 3 and norepinephrine (NE) in serum tended to increase. Concentrations of CRH and arginine vasopressin (AVP) in the hypothalamus, weight of adrenal, and content of corticosterone in adrenal and in serum did not change significantly. After 4 weeks of cold exposure, GTP binding to BAT mitochondria increased. Content of TRH in the hypothalamus recovered to that of control group, but content of TRH in the median eminence (ME) and concentration of T 3 and NE in serum increased markedly, so did the content of CRH in ME and concentration of corticosterone in serum. These results suggest that, (1) cold exposure activates the synthesis and secretion of hormones of HPT axis continuously, (2) the SNS are activated continuously in Brandt’s voles during cold exposure, (3) acute cold exposure does not activate the synthesis and secretion of CRH in hypothalamus whereas chronic cold treatment can activate the HPA axis markedly in Brandt’s voles, and (4) AVP in the hypothalamus has no significant role in the regulation of BAT thermogenesis in voles exposed to cold. Thermogenesis of BAT in cold exposed Brandt’s voles are regulated by complicated factors including HPT and HPA axis, and SNS.

关 键 词：布氏田鼠 冷暴露 产热 褐色脂肪 神经内分泌调节 

分 类 号：Q45[生物学—生理学]