重复性“饥饿/再投喂”对大鼠体重控制与能量平衡调节的影响

Effect of repeated fasting/refeeding on body weight control and energy balance regulation in rats

目的探讨经过重复性"饥饿/再投喂"饲喂方式处理的大鼠再摄取高脂食物时,与体重控制和能量平衡调节有关的瘦素(leptin)和一系列神经内分泌因子及激素的表达变化。方法设计"重复性饥饿1天/再投喂1天,持续6周"的饲喂方式(基础饲料)处理实验组(RFR),实验-高脂饲料组大鼠(RFR-LF/HF)另6周改为每天喂以高脂饲料。对照组随机分为3组,对照组喂基础饲料6周后处死,高脂饲料组改用高脂饲料,基础饲料组继续用基础饲料喂养至12周。比较各组大鼠体重、Lee’s指数和脂体比的差异,检测血脂、血清生长激素、甲状腺素、瘦素、胰岛素和血浆促肾上腺皮质激素含量,应用RT-PCR法检测下丘脑神经肽Y(NPY)、前阿黑皮素原(POMC)mRNA的表达水平。结果 RFR-LF/HF组Lee’s指数、脂体比、血清总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白(LDL)、瘦素和胰岛素水平均显著低于高脂饲料组而高于基础饲料组,下丘脑NPY mRNA表达水平显著高于高脂饲料组和基础饲料组,POMC mRNA表达水平显著低于高脂饲料组和基础饲料组。结论重复性"饥饿/再投喂"饲喂处理可降低高脂饮食诱导的肥胖程度,减轻瘦素抵抗和胰岛素抵抗,但会引起中枢神经内分泌肽表达的极度紊乱。

Objective To investigate the changes of expression on leptin,a series of neuroendocrine factors and hormones associated with body weight control and energy balance regulation of rats,which were treated with repeated fasting/refeeding and followed by fed with high fat diet.Methods Designing a repeated fasting/refeeding rats model（RFR） fed with basic stock diet on repeated cycles of 1d fasting and 1d refeeding for 6 weeks.The rats in RFR-LF/HF group were switched to a high fat diet and fed the diet every day for another 6 weeks.The control rats were randomly divided into 3 groups,control group,high-fat diet（HF） group and common fat diet（CF） group.The rats in HF and CF group were killed by the end of the 12th week.The body weight,Lee＇s index,body fat content and serum lipid,GH,T4,leptin,insulin,and plasma ACTH levels were measured.The expression of NPY and POMC mRNA in hypothalamus were detected by reverse transcription chain reaction（RT-PCR）.Results The Lee＇s index,body fat content,serum TC,TG,LDL,leptin and insulin levels of RFR-LF /HF group were lower significantly than those of HF group whereas higher significantly than those of CF group.The expression of NPY mRNA of RFR-LF /HF group were higher significantly than those of HF and CF groups,while the expression of POMC mRNA was lower significantly than that of HF and CF groups.Conclusion The feeding pattern of repeated fasting/refeeding can decrease the degree of obesity induced by high fat diet,and also reduce the leptin and insulin resistance,but cause serious disturbance of the expression of neuroendocrine peptides in the central nervous system of rat.