Wan-long Zhu, Zheng-kun Wang
Key Laboratory of Ecological Adaptive Evolution and Conservation on Animals-Plants in Southwest Mountain Ecosystem of Yunnan Province Higher Institutes College, School of Life Science of Yunnan Normal University, Kunming 650500, China.
Key Laboratory of Ecological Adaptive Evolution and Conservation on Animals-Plants in Southwest Mountain Ecosystem of Yunnan Province Higher Institutes College, School of Life Science of Yunnan Normal University, Kunming 650500, China.
Comp Biochem Physiol A Mol Integr Physiol. 2015 Jun;184:83-9. doi: 10.1016/j.cbpa.2015.02.011. Epub 2015 Feb 17.
The present study examined seasonal changes in body mass and energy metabolism in the Chaotung vole (Eothenomys olitor) and the physiological mechanisms underpinning these changes. Seasonal changes in the following parameters were measured in male E. olitor, body mass, food intake, thermogenesis, enzyme activity, masses of tissues and organs, hormone concentrations and expression of hypothalamic arcuate nucleus energy balance genes including neuropeptide Y (NPY), agouti-related protein (AgRP), pro-opiomelanocortin (POMC), and cocaine- and amphetamine-regulated transcript (CART). Body mass was constant over the year, but the masses of tissues and organs differed significantly between seasons. There were significant changes in body fat mass and serum leptin levels over the four seasons. E. olitor showed significant seasonal changes in food intake and thermogenesis, uncoupling protein 1 (UCP1) content, enzyme activity, and serum tri-iodothyronine (T3) and thyroxine (T4) levels. Moreover, mRNA expression in the hypothalamus showed significant seasonal changes. All of our results suggested that E. olitor had constant body mass over the year, which was inconsistent with the prediction of the 'set-point' hypothesis. However, body fat mass and serum leptin levels were significantly different among the four seasons, providing support for the 'set-point' hypothesis. The changes in leptin, NPY, AgRP, POMC, and CART mRNA levels may play a role in the regulation of energy intake in E. olitor. Furthermore, the role of leptin and hypothalamic neuropeptide gene in the regulation of energy metabolism and body mass may be different in animals that are acclimated to different seasons.
本研究考察了昭通绒鼠（Eothenomys olitor）体重和能量代谢的季节性变化及其潜在的生理机制。对雄性昭通绒鼠的以下参数进行了季节性变化测量：体重、食物摄入量、产热、酶活性、组织和器官质量、激素浓度以及下丘脑弓状核能量平衡基因的表达，这些基因包括神经肽Y（NPY）、刺鼠相关蛋白（AgRP）、阿黑皮素原（POMC）和可卡因及苯丙胺调节转录物（CART）。昭通绒鼠的体重在一年中保持恒定，但组织和器官质量在不同季节间存在显著差异。四季间体脂质量和血清瘦素水平有显著变化。昭通绒鼠在食物摄入量、产热、解偶联蛋白1（UCP1）含量、酶活性以及血清三碘甲状腺原氨酸（T3）和甲状腺素（T4）水平上呈现出显著的季节性变化。此外，下丘脑的mRNA表达也有显著的季节性变化。我们所有的结果表明，昭通绒鼠一年中的体重保持恒定，这与“设定点”假说的预测不一致。然而，体脂质量和血清瘦素水平在四个季节间存在显著差异，为“设定点”假说提供了支持。瘦素、NPY、AgRP、POMC和CART mRNA水平的变化可能在昭通绒鼠能量摄入的调节中发挥作用。此外，在适应不同季节的动物中，瘦素和下丘脑神经肽基因在能量代谢和体重调节中的作用可能有所不同。
