Wang Jian-Mei, Zhang Yan-Ming, Wang De-Hua
Northwest Plateau Institute of Biology, Chinese Academy of Sciences, Xining, Qinghai, 810001, China.
Comp Biochem Physiol A Mol Integr Physiol. 2006 Dec;145(4):546-53. doi: 10.1016/j.cbpa.2006.08.034. Epub 2006 Aug 30.
The present study was designed to examine whether photoperiod alone was effective to induce seasonal regulations in physiology in root voles (Microtus oeconomus) from the Qinghai-Tibetan plateau noted for its extreme cold environment. Root voles were randomly assigned into either long photoperiod (LD; 16L:8D) or short photoperiod (SD; 8L:16D) for 4 weeks at constant temperature (20 degrees C). At the end of acclimation, SD voles showed lower body mass and body fat coupled with higher energy intake than LD voles. SD greatly enhanced thermogenic capacities in root voles, as indicated by elevated basal metabolic rate (BMR), nonshivering thermogenesis (NST), mitochondrial protein content and uncoupling protein-1 (UCP1) content in brown adipose tissue (BAT). Although no variations in serum leptin levels were found between SD and LD voles, serum leptin levels were positively correlated with body mass and body fat mass, and negatively correlated with energy intake and UCP1 content in BAT, respectively. To summarize, SD alone is effective in inducing higher thermogenic capacities and energy intake coupled with lower body mass and body fat mass in root voles. Leptin is potentially involved in the photoperiod induced body mass regulation and thermogenesis in root voles.
本研究旨在探讨仅光周期是否能有效诱导来自以极端寒冷环境著称的青藏高原的根田鼠（Microtus oeconomus）生理上的季节性调节。根田鼠被随机分为长光周期组（LD；16小时光照：8小时黑暗）或短光周期组（SD；8小时光照：16小时黑暗），在恒温（20摄氏度）条件下饲养4周。适应期结束时，与长光周期组田鼠相比，短光周期组田鼠体重和体脂更低，但能量摄入量更高。短光周期极大地增强了根田鼠的产热能力，棕色脂肪组织（BAT）中的基础代谢率（BMR）、非颤抖性产热（NST）、线粒体蛋白含量和解偶联蛋白1（UCP1）含量升高表明了这一点。尽管短光周期组和田鼠长光周期组田鼠之间血清瘦素水平没有差异，但血清瘦素水平分别与体重和体脂量呈正相关，与能量摄入量和棕色脂肪组织中的UCP1含量呈负相关。总之，仅短光周期就能有效诱导根田鼠产生更高的产热能力和能量摄入量，同时降低体重和体脂量。瘦素可能参与了根田鼠光周期诱导的体重调节和产热过程。
