短光照诱导达乌尔黄鼠产热  

Short photoperiod induces the thermogenesis in Daurian ground squirrels

作　　者：黄晨西[1] 林琳[1] 李庆芬[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,北京100875

出　　处：《兽类学报》2006年第4期346-353,共8页Acta Theriologica Sinica

基　　金：国家自然科学基金资助项目(39970124)

摘　　要：本文通过测定静止代谢率(RMR)、非颤抖性产热(NST)、线粒体呼吸酶、脂肪代谢酶活力、褐色脂肪组织(BAT)线粒体GTP结合能力、下丘脑促甲状腺激素释放激素(TRH)和促肾上腺激素释放激素(CRH)等指标,探讨短光照对达乌尔黄鼠产热的诱导和调节。结果表明,温暖(22℃)短光照(8D∶6L)组,达乌尔黄鼠的RMR、NST、肝脏和BAT线粒体细胞色素C氧化酶活力以及BAT线粒体GTP结合能力均明显高于温暖长光照(16D∶8L)组中的动物,而体重、BAT重量、肝细胞呼吸、BATα-磷酸甘油氧化酶活力则没有明显变化。短光照组黄鼠下丘脑TRH水平显著高于长光照组,而血清中三碘甲腺原氨酸(T3)及甲状腺素(T4)浓度、T3/T4以及BAT中T4-5’脱碘酶的活性没有明显变化。短光照组黄鼠下丘脑CRH水平显著高于对照组,而肾上腺皮质酮含量无明显变化。结果表明短光照能够诱导达乌尔黄鼠产热增加,主要是通过激活细胞色素C氧化酶活性和增加BAT中解偶联蛋白浓度;短光照可能激活下丘脑TRH和CRH,但它们没有直接诱导产热增加,推测其增加了黄鼠潜在的产热能力。Thermogenesis and thermoregulation induced by short photoperiod were investigated in Daurian ground squirrels （ Spermophilus dauricus ） by measuring resting metabolic rate （ RMR ） , nonshivering thermogenesis （ NST ） , activity of cytochrome C oxidase （ CCO） of liver and brown adipose tissues （ BAT） , BAT mitoehondrial GTP-binding capacity, and hypothalamic thyrotropin-releasing hormone （ TRH ） and corticotrophin-releasing hormone （CRH） levels in squirrels. The resuits showed that the RMR, NST, CCO activity, and BAT mitochondrial GTP-binding capacity were markedly increased by exposure to short photoperiod （8D： 16L, SP） and constant ambient temperature （22 ± 2℃） relative to those for long photoperiod （ 16D： 8L, 22 ±2℃, LP） , while body weight and BAT mass, hepatic mitochondrial respiration, and BAT α-glycerophosphate oxidase activity were not significantly changed. The short photoperiod induced higher hypothalamic TRH and CRH levels than did the LP. However, the serum concentration of triiodothyronine （T3）, thyroxine （T4） , the ratio of T3 and T4, the activity of T45 ＇ -deiodinase in BAT, and the adrenal corticosterone level showed no significantly change. The results suggest that the short photoperiod may induce an increased thermogenesis in Daurian ground squirrel＇ s through activating CCO and enhancing uncoupling-protein levels in BAT, and simultaneously activating hypothalamic TRH and CRH that do not directly induce an increased hermogenesis but may be a potential factor.

关 键 词：短光照 产热 达乌尔黄鼠 

分 类 号：Q958.1[生物学—动物学]