胆碱对高脂胁迫的团头鲂肝脏抗氧化、组织结构和免疫力的影响  

Effects of choline on hepatic antioxidant status,ultrastructure and innate immunity in blunt snout bream(Megalobrama amblycephala) fed high-fat diet

作　　者：张定东[1] 李俊怡[1] 王冰柯 李向飞[1] 蒋广震[1] 李鹏飞[1] 蔡万存[1] 刘文斌[1] ZHANG Dingdong LI Junyi WANG Bingke LI Xiangfei JIANG Guangzhen LI Pengfei CAI Wancun LIU Wenbin(Key Laboratory of Aquatic Animal Nutrition and Feed Science of Jiangsu Province, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China)

机构地区：[1]南京农业大学动物科技学院,江苏省水产动物营养重点实验室,江苏南京210095

出　　处：《水产学报》2017年第3期438-447,共10页Journal of Fisheries of China

基　　金：国家自然科学基金(C190401);国家大宗淡水鱼产业技术体系资金(CARS-49-20)~~

摘　　要：以初始体质量(42.20±0.34)g团头鲂为研究对象,研究饲料中添加胆碱对高脂胁迫团头鲂肝脏抗氧化、组织结构和免疫力的影响。实验采用2×2因子设计方法,共配置2个脂肪水平(5%和15%)和2个胆碱水平(1200和2200 mg/kg)的等氮饲料4组。养殖实验在室内循环水系统中进行,养殖周期为8周。养殖实验结束后进行血液和肝脏生化指标、肝脏抗氧化指标和非特异性免疫指标等的检测分析,以及观察肝细胞的超微结构变化。结果显示,当饲料中添加1200 mg/kg胆碱时,随着脂肪水平的升高,团头鲂肝脏脂肪含量和甘油三酯浓度显著增加,而血浆中谷草转氨酶(AST)和谷丙转氨酶(ALT)活性则显著上升;肝脏中丙二醛(MDA)含量、总超氧化物歧化酶(t-SOD)活性、过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GPX)活性等显著升高;血液中白细胞数、溶菌酶活性、总蛋白和球蛋白水平以及还原型谷胱甘肽(GSH)活性显著降低;超微结构观察到肝细胞中存在大量脂滴,伴随着细胞核变性、核膜残缺、线粒体水肿等异常现象。这些结果表明高脂日粮不仅导致肝细胞的结构和功能的损伤,而且造成肝脏氧化应激和机体免疫力的下降。在高脂饲料(15%脂肪)中添加2200 mg/kg胆碱,可显著降低肝脏脂肪含量、血浆谷草转氨酶(AST)和谷丙转氨酶(ALT)活性,显著降低肝脏丙二醛(MDA)含量、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性,并显著提高白细胞数和球蛋白水平以及还原型谷胱甘肽(GSH)活性,同时肝细胞形态及细胞器结构也趋于正常。研究表明,添加适量胆碱能够减少肝脏脂肪沉积,维持肝脏结构和功能的正常,并增强团头鲂抗氧化能力和机体免疫力,继而保持鱼体的健康。This study aimed to delineate the potentially beneficial effects of choline on the liver histopathology,antioxidative status and innate immunity in blunt snout bream（Megalobrama amblycephala） fed high-fat diet.Fish[weight：（42.20±0.34） g] were fed four experimental diets containing two dietary lipid levels（5% and 15%） and two choline levels（1200 and 2200 mg/kg） in an indoor circulatory system for eight weeks.After the feeding trial,fish were sampled for analysis of plasma and hepatic lipid metabolites,antioxidant enzymes,haematoimmunological parameters and hepatocyte ultrastructural examination.The results showed that high-fat diet significantly increased liver lipid accumulation,aspartate aminotransferase（AST） and alanine aminotransferase（ALT） activities,malondialdehyde（MDA） concentration,activities of total superoxide dismutase（SOD）,catalase（CAT） and glutathione peroxidase（GPX）;meanwhile,high-fat diet remarkably reduced blood leucocyte counts,plasma lysozyme activity,total protein and globulin contents and glutathione（GSH）.In addition,obvious ultrastructure abnormalities were observed in the hepatocytes of fish fed 15% lipid and 1200 mg/kg choline with apparent alterations involving mitochondrion,endoplasmic reticulum,nucleus and cell membrane.The results indicated that high-fat diet induced significant liver histological alterations,severe oxidative stress and depressed innate immunity of blunt snout bream.However,high dose of choline in high-fat diet significantly decreased liver lipid content,plasma AST and ALT activities,liver MDA concentration,hepatic SOD and CAT activities,and enhanced blood leucocyte counts and globulin protein level;meanwhile,the structures of hepatocyte organelles were normal.In summary,choline could reduce hepatic excess fat deposition,maintain normal structure and function of liver,and enhance anti-oxidative capacity and innate immunity,and hence it could keep the health of the fish.

关 键 词：团头鲂 胆碱 高脂 抗氧化 免疫 超微结构 

分 类 号：S963.73[农业科学—水产养殖]