褪黑素调节雄性大鼠脂肪代谢的研究

The Study of Melatonin Regulating Lipid Metabolism in Male Rats

旨在研究褪黑素(Melatonin,MT)对雄性大鼠脂肪代谢的影响及其对不同脂肪代谢酶/因子的作用,初步揭示其调节脂肪代谢的机理。选择20只日龄、体重接近的SD雄性大鼠随机平均分为2组,分别为对照组(ND)和褪黑素处理组(ND+MT)。ND+MT组除饲喂正常的饲粮外,每天灌服10mg·kg-1 BW的MT溶液。试验60d后采血,分析血液生化、激素及脂代谢相关指标;试验结束后处死大鼠,摘取肝组织,分离腹部各部位脂肪组织并称重,采集肝组织样品用于基因芯片检测和相关分子分析。结果表明:1)ND+MT组大鼠肝重、肝指数、大网膜重、大网膜指数、附睾脂肪重显著降低(P<0.05)。血清低密度脂蛋白显著降低(P<0.05),高密度脂蛋白、总胆固醇含量下降,极低密度脂蛋白含量升高;肝组织中长链脂肪酸含量显著降低(P<0.05)。2)基因芯片和荧光定量PCR检测结果表明,肝组织中脂肪分解相关因子CPT1的mRNA表达显著上调(P<0.05),脂肪分解相关酶ALDH3a2的mRNA表达升高(0.05<P<0.1),脂肪合成相关酶ACSL3、FAS的mRNA表达显著下调(P<0.05)。结果提示,MT可显著影响脂肪的代谢,减少内脏脂肪的含量,其机制与相关激素及肝脂肪代谢相关酶(因子)对MT的不同反应有关。

The present study aimed to investigate the effect of melatonin （MT） on lipid metabolism and its effect on lipid metabolism enzymes and factors, and to reveal the mechanism of lipid metabolism in male rats. Twenty SD male rats with similar age and body weight were randomly divided into 2 groups （10 rats per group ）,which were control group （normal diet, ND） and MT treated group （normal diet with oral melatonin solution, ND＋MT）. The MT was administrated at 10 mg·kg-1 BW per day. The experiment lasted for 60 days. At the end of the experiment, blood sample were collected to extract plasma to detect biochemical, hormonal and lipid metabolism related indicators; The rats were sacrificed, the liver and the adipose mass in the abdomen, such as omentum, perirenal fat and epididymal fat was separated and weighed. In additon, liver tissue was sampled for Gene chip and related molecules analysis. The result showed that： 1） The liver weight, liver index, omental weight, omental index and epididymal fat weight in ND ＋ MT group were decreased significantly （P〈0.05）. Low density lipoprotein in serum was significantly decreased （P〈0. 05）, high density lipoprotein and total cholesterol in serum were decreased, while very low density lipoprotein increased. The contents of hepatic long chain fatty acids （LCFA） was significantly decreased （P〈0.05）. 2） Gene chip and fluorescent quantitative PCR result showed that the mRNA expression of lipolysis related factors and enzymes, such as CPT1 （P〈0.05） and ALDH3a2 （0. 05〈P〈0. 1） in liver tissue were increased, while the mRNA expression of fat synthesis related enzyme, such as ACSL3 and FAS was decreased significantly （P〈0.05）. MT can greatly affect the lipid metabolism with the reduction of visceral fat, its mechanism is connected with the response of hormones and lipid metabolism related enzymes or factors to MT.