高山姬鼠下丘脑神经肽表达量的季节性变化

Seasonal Variations of Hypothalamic Neuropeptide Expression in Chevrier′s Field Mouse(Apodemus chevrieri)

为阐明高山姬鼠(Apodemus chevrieri)下丘脑神经肽表达量在季节性变化条件下对其体重调节的作用,测定了不同季节高山姬鼠的体重、体脂含量、食物摄入量以及血清瘦素浓度和神经肽Y(NPY)、刺鼠相关蛋白(Ag RP)、阿片促黑色素原(POMC)和可卡因-安他非明转录调节肽(CART)表达量。采用食物平衡法测定高山姬鼠的食物摄入量,体脂含量用索氏抽提法进行测定,采用实时荧光PCR仪测定下丘脑神经肽表达量。采用单因素方差分析或协方差分析进行检验,相关性采用Pearson相关分析。高山姬鼠的体重和体脂均出现了季节性变化,冬季较低,夏季较高。食物摄入量季节性差异显著,冬季较高,夏季最低。血清瘦素含量也出现了季节性变化,与体脂变化趋势类似,瘦素含量与脂肪含量呈正相关关系。下丘脑神经肽NPY、Ag RP、POMC和CART表达量季节性差异显著。食物摄入量与NPY和Ag RP负相关,与POMC和CART正相关。以上结果表明,高山姬鼠在季节性变化过程中冬季降低体重、体脂,增加摄入量来维持生存。瘦素通过作用于下丘脑神经肽基因来调节高山姬鼠的体重平衡。

The aim of the present study was to examine the effects of hypothalamic neuropeptide genes expression on body mass regulation under seasonal variations in Chevrier＇s Field Mouse （Apodemus chevrieri）. Body mass, body fat mass, food intake, serum leptin levels and hypothalamic neuropeptide neuropeptide Y （NPY）, agouti-related peptide （AgRP）, pro-opiomelanocortin （POMC） and cocaine and amphetamine regulated transcript peptide （CART） expression were measured in Chevrier＇s Field Mouse Food intake was measured by food equity, body fat was extracted from the dried carcass by ether extraction in a Soxhlet apparatus, hypothalamic neuropeptides genes expression was measured by real-time q-PCR, Data were analyzed using One-way ANOVA or One-way ACNOVA, and associations were judged by Pearson-correlation analysis. The results showed that body mass and body fat mass showed seasonal variations, higher in summer and lower in winter （Fig. 1）, and food intake also showed significant seasonal variability, higher in winter and lower in summer （Fig. 1）. Serum leptin level also had similar seasonal variation, showing similar trend as body fat mass （Fig. 2）, and serum leptin level showed a positive correlation with body fat mass （Fig. 3）. Expression of hypothalamic neuropeptide NPY, AgRP, POMC and CART showed significant seasonal differences （Fig. 4）. The above results suggest that Chevrier＇s Field Mouse reduces body mass, body fat mass, increases food intake to survive in winter under seasonal changes. Leptin may play a regulatory role in body mass by acting on hypothalamic neuropeptide in Chevrier＇s Field Mouse.