动物营养学报    2019, Vol. 31 Issue (7): 3197-3206    PDF    
饲料中添加丙氨酰-谷氨酰胺二肽对黄颡鱼幼鱼生长性能、抗氧化能力、免疫应答能力及抗逆能力的影响
李雪1 , 张木子1 , 黎明1 , 章倩1 , 王日昕1 , 姜海波2,3     
1. 宁波大学海洋学院, 宁波 315211;
2. 贵州大学动物科学学院, 贵阳 550025;
3. 贵州大学高原山地动物遗传育种与繁殖教育部重点实验室, 贵阳 550025
摘要: 本试验旨在研究饲料中添加丙氨酰-谷氨酰胺二肽(AGD)对黄颡鱼幼鱼生长性能、抗氧化能力、免疫应答能力及抗逆能力的影响。以平均体重为(1.98±0.01)g的黄颡鱼幼鱼为研究对象,随机分成5组,每组3个重复,每个重复30尾鱼,分别投喂添加0(对照)、0.25%、0.50%、0.75%和1.00% AGD的5种试验饲料,5种试验饲料中AGD含量的实测值依次为0.08%、0.23%、0.56%、0.69%和1.09%。摄食生长试验持续56 d。结果表明:随着饲料中AGD添加量的增加,试验鱼的增重、特定生长率以及血清总蛋白、白蛋白、球蛋白、补体3和补体4含量与超氧化物歧化酶、过氧化氢酶、谷胱甘肽、溶菌酶、碱性磷酸酶和酸性磷酸酶活性均先增加后降低,0.50%和0.75% AGD组均显著高于对照组(P < 0.05)。饲料中添加不同水平的AGD均显著提高了试验鱼血清总抗氧化能力(P < 0.05),显著降低了丙二醛含量(P < 0.05)。氨氮胁迫96 h后,对照组试验鱼大脑中氨和谷氨酰胺含量显著高于各AGD添加组(P < 0.05),同时累积死亡率也显著高于各AGD添加组(P < 0.05)。由此可见,饲料中添加适宜水平的AGD能够提高黄颡鱼幼鱼的生长性能、抗氧化能力、免疫应答能力及抗逆能力;基于特定生长率的二次回归模型拟合,获得黄颡鱼幼鱼饲料中AGD的最适添加量为0.56%;综合考虑生长性能、抗氧化能力、免疫应答能力及抗逆能力,推荐黄颡鱼幼鱼饲料中AGD的添加量为0.50%~0.75%。
关键词: 丙氨酰-谷氨酰胺二肽    黄颡鱼幼鱼    生长性能    抗氧化能力    免疫应答能力    抗逆能力    
Effects of Alanyl-Glutamine Dipeptide Supplementation on Growth Performance, Antioxidant Status, Immune Response and Stress Resistance of Juvenile Yellow Catfish (Pelteobagrus fulvidraco)
LI Xue1 , ZHANG Muzi1 , LI Ming1 , ZHANG Qian1 , WANG Rixin1 , JIANG Haibo2,3     
1. School of Marine Sciences, Ningbo University, Ningbo 315211, China;
2. College of Animal Sciences, Guizhou University, Guiyang 550025, China;
3. Key Laboratory for Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region of Ministry of Education, Guizhou University, Guiyang 550025, China
Abstract: A 56-day feeding trial was conducted to determine the alanyl-glutamine dipeptide (AGD) supplementation on growth performance, antioxidant status, immune response and stress resistance of juvenile yellow catfish (Pelteobagrus fulvidraco). Juvenile yellow catfish with an average body weight of (1.98±0.01) g were randomly assigned to 5 groups with 3 replicates per group and 30 juvenile fish per replicate. Juvenile fish in the 5 groups were fed 5 experimental diets supplemented with 0 (control) 0.25%, 0.50%, 0.75% and 1.00% AGD, and the measured AGD contents in the 5 experimental diets were 0.08%, 0.23%, 0.56%, 0.69% and 1.09%, respectively. The results showed that the weight gain, specific growth rate, serum total protein, albumin, globulin, complement 3, complement 4 contents and superoxide dismutase, catalase, glutathione, lysozyme, alkaline phosphatase, acid phosphatase activities were firstly increased and then increased with dietary AGD supplemental level increasing, and above indexes in 0.50% and 0.75%AGD groups were significantly higher than those in control group (P < 0.05). Diet supplemented different levels of AGD could significantly increase the serum total antioxidant capacity (P < 0.05), but significantly decrease the serum malondialdehyde content (P < 0.05). After 96 h post-challenge on ammonia exposure, the cumulative mortality, brain ammonia and glutamate contents in control group were significantly higher than those in each AGD supplementation groups (P < 0.05). In conclusion, suitable level of AGD supplemented into diets can increase the growth performance, antioxidant status, immune response and stress resistance of juvenile yellow catfish. The optimal dietary AGD supplemental level is estimated to be 0.56% in the diet of juvenile yellow catfish by quadratic regression analysis base on specific growth rate. By a comprehensive consideration of growth performance, antioxidant status, immune response and stress resistance, the supplemental level of 0.50% to 0.75% AGD is recommended in diets of juvenile yellow catfish.
Key words: alanyl-glutamine dipeptide    juvenile yellow catfish    growth performance    antioxidant status    immune response    stress resistance    

谷氨酰胺(Gln)是一种存在于动物体内且含量十分丰富的非必需氨基酸,对于维持机体正常的生理活动发挥着重要作用[1],如:充当氨基酸、核苷酸及蛋白质合成的前体物质[2];维持血浆Gln含量及酸碱平衡[3];参与组织间氨的运输及抗氧化因子合成[4]。外源Gln摄入量下降会导致小鼠肠黏膜萎缩及肠道细菌移位[5],影响组织中谷胱甘肽的合成[6]。在水生动物研究中发现,饲料中添加Gln可以提高鲤鱼(Cyprinus carpio)[7]、美国红鱼(Sciaenops ocellatus)[8]、杂交鲟(Acipenser schrenckii×Huso dauricus)[9]、斑点叉尾(Ictalurus punctatus)[10]和大菱鲆(Scophthalmus maximus)[11]的生长性能、饲料效率及存活率[7]。然而,Gln在水中并不稳定,易生成有毒物质[12],相较而言,作为Gln的主要替代物——丙氨酰-谷氨酰胺二肽(AGD),在低pH和高温环境下更加稳定[9]。迄今,较多的研究主要关注Gln对鱼类生长性能、抗氧化能力及免疫应答能力的调节,而针对AGD的研究却鲜见报道。

黄颡鱼(Pelteobagrus fulvidraco)营养丰富,生长迅速,是我国南方优良的水产养殖品种之一,据《2017中国渔业统计年鉴》权威统计,2016年全国黄颡鱼总产量已达41万t[13]。作为一种重要的经济养殖品种,其营养需求研究已有较多报道,包括:蛋白质和氨基酸[14]、脂质和脂肪酸[15]、维生素[16]及矿物质[17]等。然而,AGD在黄颡鱼饲料中的最适添加量迄今尚未见到报道。本研究通过配制不同AGD含量的饲料,开展摄食生长试验,试图探究AGD对黄颡鱼幼鱼生长性能、抗氧化能力、免疫应答能力及抗逆能力的影响,并查明AGD在黄颡鱼人工配合饲料中的最适添加量,为黄颡鱼养殖生产提供基础数据。

1 材料与方法 1.1 试验饲料

试验饲料以秘鲁鱼粉、豆粕和小麦面筋粉作为蛋白质源,以鱼油、豆油和大豆卵磷脂作为脂肪源,配制AGD(购自Sigma公司,纯度为99.9%)添加量分别为0(对照)、0.25%、0.50%、0.75%和1.00%的5种试验饲料,5种试验饲料中AGD含量的实测值依次为0.19%、0.23%、0.56%、0.69%和1.09%。将试验饲料加工成粒径分别为2和4 mm的颗粒料,室温干燥至水分含量 < 10%,-20 ℃自封袋中储存备用。试验饲料组成及营养水平见表 1

表 1 试验饲料组成及营养水平(干物质基础) Table 1 Composition and nutrient levels of experiment diets (DM basis)
1.2 试验动物及取样

黄颡鱼幼鱼购自浙江省湖州市某养殖场,暂养14 d后,随机挑选450尾体格健康、大小均匀、平均体重为(1.98±0.01) g的黄颡鱼幼鱼,分配到15个300 L塑料养殖桶中,每桶30尾。每种试验饲料投喂3桶试验鱼,每天饱食投喂2次(07:00—08:00、17:30—18:00),持续56 d,每天记录投喂量。试验期间水质参数如下:水温(28.00±2.00) ℃,溶解氧浓度(8.00±0.55) mg/L,pH 6.40~6.60,总氨氮浓度 < 0.04 mg/L,亚硝酸盐浓度 < 0.50 mg/L,保持自然光照。

摄食生长试验结束后,禁食24 h,经MS-222麻醉后记录每桶试验鱼的总重及存活数。每桶随机挑选3尾试验鱼,-20 ℃保存,用于体成分分析;每桶另随机取3尾试验鱼,尾静脉取血,836×g离心10 min制备血清,-80 ℃保存,用于血清生化、抗氧化及免疫指标测定;取血后的试验鱼,解剖获取肝脏,称重并计算肝体指数。

1.3 氨氮胁迫试验

摄食生长试验结束后,每桶随机选择20尾试验鱼,暴露于总氨氮浓度为9 mg/L(半数致死剂量)[18]的水体(pH 6.40~6.60)中96 h,统计累积死亡率;试验鱼经MS-222麻醉后,解剖获取大脑,-80 ℃保存,用于大脑中氨和Gln含量分析。

1.4 指标测定

参考AOAC(2000)[19]标准方法测定全鱼及饲料中粗蛋白质、粗脂肪、粗灰分及水分的含量;参考叶应妩等[20]描述的方法测定血清总蛋白、白蛋白、球蛋白、葡萄糖、胆固醇、甘油三酯、高密度脂蛋白、低密度脂蛋白含量以及天冬氨酸转氨酶和丙氨酸转氨酶活性,所有测试均采用商业试剂盒(南京建成生物工程研究所生产);参考Li等[18]描述的方法测定血清总抗氧化能力,超氧化物歧化酶、过氧化氢酶、谷胱甘肽活性及丙二醛含量,所有测试均采用商业试剂盒(南京建成生物工程研究所生产),操作步骤严格按照说明书进行;参考Li等[18]描述的方法测定血清溶菌酶、碱性磷酸酶和酸性磷酸酶活性,所有测试均采用商业试剂盒(南京建成生物工程研究所生产),操作步骤严格按照说明书进行;采用商业试剂盒(浙江伊利康生物技术有限公司生产)测定血清补体3(C3)、补体4(C4)及总免疫球蛋白含量。

取0.5 g冷冻大脑组织在液氮中研磨,在6%三氯乙酸中24 000×g匀浆20 s,匀浆液于10 000×g、4 ℃条件下离心15 min,取上清后参考Bergmeyer等[21]推荐的方法测定大脑中氨的含量,参考Ip等[22]推荐的方法测定大脑中Gln的含量。

1.5 计算方法

增重(weight gain, g)=终末体重-初始体重;

特定生长率(specific growth rate, %/d)=

100×(ln终末体重-ln初始体重)/试验天数;

摄食量(feed intake, g/尾)=总摄食量/

[(初始鱼尾数+终末鱼尾数)/2];

饲料转化率(feed conversion ratio)=

饲料投喂量/增重;

肝体比(hepatosomatic index, %)=

100×肝脏重/终末体重;

存活率(survival rate, %)=100×

终末存活尾数/初始尾数。

1.6 统计分析

试验数据采用SPSS 18.0.0软件的单因素方差分析(one-way ANOVA)程序进行统计学处理,结果以平均值±标准误(mean±SE)表示,如果组间差异显著(P < 0.05),则采用Tukey’s法进行多重比较。

2 结果与分析 2.1 饲料中添加AGD对黄颡鱼幼鱼生长性能的影响

表 2可知,试验鱼的存活率(各组均高于96.00%)、摄食量、饲料转化率及肝体比在各组间无显著差异(P>0.05);试验鱼的终末体重、增重及特定生长率随着饲料中AGD添加量的增加先升高后降低,均在AGD添加量为0.50%时达到最高,AGD添加量继续增加到0.75%时未出现显著差异(P>0.05),但AGD添加量超过0.75%则显著降低(P < 0.05)。

表 2 饲料中添加AGD对黄颡鱼幼鱼生长性能的影响 Table 2 Effects of AGD supplementation on growth performance of juvenile yellow catfish

基于特定生长率的二次回归模型拟合,获得黄颡鱼幼鱼饲料中AGD的最适添加量为0.56%(y=-0.33x2+0.372 5x+2.761 9,R2=0.980;y表示特定生长率,x表示饲料中AGD添加量),见图 1

图 1 基于特定生长率对饲料中 AGD添加量进行二次回归分析 Fig. 1 Quadratic regression analysis of SGR against dietary AGD supplemental level
2.2 饲料中添加AGD对黄颡鱼幼鱼体成分的影响

表 3可知,饲料中添加不同水平的AGD对全鱼水分、粗蛋白质、粗脂肪和粗灰分含量均未产生显著影响(P>0.05)。

表 3 饲料中添加AGD对黄颡鱼幼鱼体成分的影响 Table 3 Effects of AGD supplementation on body composition of juvenile yellow catfish
2.3 饲料中添加AGD对黄颡鱼幼鱼血清生化指标的影响

表 4可知,血清总蛋白、白蛋白和球蛋白含量随着饲料中AGD添加量的增加先升高后降低,0.50%和0.75%AGD组间差异不显著(P>0.05),二者均显著高于其他各组(P < 0.05);饲料中添加不同水平的AGD对血清葡萄糖、胆固醇、甘油三酯、高密度脂蛋白、低密度脂蛋白含量以及天冬氨酸转氨酶和丙氨酸转氨酶活性均未产生显著影响(P>0.05)。

表 4 饲料中添加AGD对黄颡鱼幼鱼血清生化指标的影响 Table 4 Effects of AGD supplementation on serum biochemical indexes of juvenile yellow catfish
2.4 饲料中添加AGD对黄颡鱼幼鱼血清抗氧化指标的影响

表 5可知,饲料中添加不同水平的AGD均显著提高了血清总抗氧化能力(P < 0.05);血清超氧化物歧化酶、过氧化氢酶及谷胱甘肽活性随着饲料中AGD添加量的增加先升高后降低,0.50%和0.75% AGD组间差异不显著(P>0.05),但二者均显著高于对照组和1.00%ADG组(P < 0.05);随着饲料中AGD添加量的增加,血清丙二醛含量呈先降低后升高的趋势,最低值出现在0.50%AGD组,显著低于对照组以及0.75%和1.00%ADG组(P < 0.05)。

表 5 饲料中添加AGD对黄颡鱼幼鱼血清抗氧化指标的影响 Table 5 Effects of AGD supplementation on serum antioxidant indexes of juvenile yellow catfish
2.5 饲料中添加AGD对黄颡鱼幼鱼免疫应答能力的影响

表 6可知,饲料中添加不同水平的AGD对血清总免疫球蛋白含量未产生显著影响(P>0.05);血清溶菌酶、碱性磷酸酶、酸性磷酸酶活性以及补体3和补体4含量随着饲料中AGD添加量的增加先升高后降低,0.50%和0.75%AGD组均显著高于对照组(P < 0.05)。

表 6 饲料中添加AGD对黄颡鱼幼鱼免疫应答能力的影响 Table 6 Effects of AGD supplementation on immune response of juvenile yellow catfish
2.6 饲料中添加AGD对黄颡鱼幼鱼抗逆能力的影响

表 7可知,氨氮胁迫96 h后,对照组试验鱼大脑中氨和Gln含量显著高于各AGD添加组(P < 0.05),同时累积死亡率也显著高于各AGD添加组(P < 0.05),而各AGD添加组之间无显著差异(P>0.05)。

表 7 氨氮胁迫96 h后黄颡鱼幼鱼的累积死亡率及大脑中氨和Gln的含量 Table 7 Cumulative mortality and contents of ammonia and Gln in brain of juvenile yellow catfish exposed to ammonia at 96 h
3 讨论

已有研究指出,过低或过高的AGD摄入量均会对鱼类的生长造成负面影响[23]。在本研究中,相比对照组而言,饲料中添加AGD显著提高了试验鱼的生长性能(如增重和特定生长率),并发现黄颡鱼饲料中AGD的适宜添加量为0.50%~0.75%。然而,不同鱼类对于饲料中AGD的最适需求量存在极大差异,如杂交鲟为1.00%[9]、鲤鱼为0.82%[2]和1.00%[24]、军曹鱼(Rachycentron canadum)为0.50%[25],范围为0.50%~1.00%,差异的出现可能与饲料蛋白质源、蛋白质水平、试验条件、鱼的种类和大小有关。前人在大鼠上的研究发现,相比Gln添加组,摄入AGD的大鼠肌肉和肝脏中Gln的含量更高,表明在饲料中添加AGD要比Gln更加稳定和高效[26]。在杂交鲟的研究中发现,饲料中添加Gln和AGD均能提高其生长性能,然而,最适添加量却存在很大的差异:1.00%AGD或3.00%~5.00%Gln[9]。Anderson等[27]指出,Gln能够被谷氨酰胺酶水解生成谷氨酸,而谷氨酸则作为谷氨酰胺合成酶的底物合成Gln,这个循环在哺乳动物研究中已得到证实,但在鱼类中是否存在并不十分清楚。已有研究发现,大多数鱼类能够依赖谷氨酰胺合成酶,催化谷氨酸合成Gln[25]。然而,少数一些鱼类却不能有效的利用谷氨酸合成Gln,如斑点叉尾[28]、牙鲆(Paralichthys olivaceus)[29]、金头鲷(Sparus aurata)[30]和大菱鲆[31]。本研究发现,对照组黄颡鱼幼鱼的增重(7.27 g)显著低于各AGD添加组,表明黄颡鱼自身Gln合成能力较低。

AGD(或Gln)在鱼体内均能够发挥抗氧化作用,本研究发现,饲料中添加0.25%~0.75%的AGD显著提高了试验鱼血清总抗氧化能力以及超氧化物歧化酶、过氧化氢酶和谷胱甘肽的活性,同时降低了丙二醛的含量。类似的发现在其他鱼类研究中也屡见报道。Xu等[2]发现,在鲤鱼饲料中添加7.5~15.0 g/kg AGD能够显著提高肠道、肝胰脏、血浆和肌肉中谷胱甘肽过氧化物酶、谷胱甘肽及超氧化物歧化酶的活性,并降低丙二醛的含量;Liu等[32]报道,在饲料中添加Gln可显著降低舌鳎(Cynoglossus semilaevis)体内丙二醛的含量;Coutinho等[30]研究发现,金头鲷摄食Gln可以提高肠道超氧化物歧化酶活性;Chen等[33]研究发现,Gln可以完全阻止过氧化氢(H2O2)对鲤鱼肠细胞抗氧化酶活性的抑制。Luo等[34]提出,AGD(或Gln)是谷胱甘肽合成的前体物质,而谷胱甘肽是主要的内源性抗氧化剂。本研究发现,饲料中添加适宜的AGD,能够通过提高谷胱甘肽的活性来增强机体的抗氧化能力。

血清总蛋白包括白蛋白和球蛋白,其中,白蛋白具有多种生理功能,包括维持血浆胶体渗透压平衡、调节微血管通透性及炎症基因转录等[35],而球蛋白在脊椎动物特异性和非特异性免疫中发挥重要作用[36]。Chen等[37]报道,饲料中添加Gln可以提高哺乳动物血清总蛋白含量及免疫力。在本研究中,高剂量(0.50%~0.75%)AGD添加组试验鱼部分血清生化指标(总蛋白、白蛋白和球蛋白含量)和免疫应答指标(溶菌酶、酸性磷酸酶活性及补体3、补体4含量)显著高于低剂量(0~0.25%)AGD添加组。Xu等[2]也发现了类似的现象,即饲料中添加AGD有助于提高鲤鱼淋巴细胞和巨噬细胞的增殖及细胞因子的产生,并促进溶菌酶的分泌。作为免疫防御的第1道防线,溶菌酶和补体能够有效的阻止病原微生物的黏附和定植[38]。Xu等[2]发现,饲料中添加5 g/kg AGD能够显著提高鲤鱼血浆中补体3和补体4的含量[2],这与本研究所得结果是一致的。然而,Bartell等[39]发现,与1%Gln添加量相比,4%Gln添加量显著降低了鸡血浆中免疫球蛋白A的含量。本研究也发现,饲料中AGD添加量超过0.75%会对试验鱼的免疫应答能力造成抑制。然而,其分子机制迄今尚不十分清楚,有待进一步调查。

在本研究中,试验鱼被暴露在氨氮半致死剂量(总氨氮浓度为9 mg/L)的水体中96 h,0.25%~1.00%AGD组试验鱼大脑中氨的含量显著低于对照组,而对照组的累积死亡率为21.82%,显著高于各AGD添加组,但各AGD添加组之间累积死亡率差异不显著。Shah等[40]报道,动物大脑中铵根(NH4+)过度积累,造成Gln合成紊乱,是导致高血氨症死亡的重要因素之一。在本研究中,饲料中添加不同水平AGD后试验鱼大脑中Gln含量均显著降低。Rose[41]指出,组织中Gln的含量往往随着神经细胞中Gln的释放逐渐增加,而大脑中Gln含量过高将激活N-甲基-D-天冬氨酸(NMDA)受体,导致神经细胞中蛋白质结构被破坏。本研究结果表明,饲料中添加AGD可以增加Gln的吸收,减少Gln的释放。

4 结论

综上,饲料中添加适宜水平的AGD能够提高黄颡鱼幼鱼的生长性能、抗氧化能力、免疫应答能力及抗逆能力;基于特定生长率的二次回归模型拟合,获得黄颡鱼幼鱼饲料中AGD的最适添加量为0.56%;综合考虑生长性能、抗氧化能力、免疫应答能力及抗逆能力,推荐黄颡鱼幼鱼饲料中AGD的添加量为0.50%~0.75%。

参考文献
[1]
FELIG P. Amino acid metabolism in man[J]. Annual Review of Biochemistry, 1975, 44: 933-955. DOI:10.1146/annurev.bi.44.070175.004441
[2]
XU H, ZHU Q, WANG C A, et al. Effect of dietary alanyl-glutamine supplementation on growth performance, development of intestinal tract, antioxidant status and plasma non-specific immunity of young mirror carp (Cyprinus carpio L.)[J]. Journal of Northeast Agricultural University, 2014, 21(4): 37-46. DOI:10.1016/S1006-8104(15)30018-0
[3]
CRUZAT V F, TIRAPEGUI J. Effects of oral supplementation with glutamine and alanyl-glutamine on glutamine, glutamate, and glutathione status in trained rats and subjected to long-duration exercise[J]. Nutrition, 2009, 25(4): 428-435. DOI:10.1016/j.nut.2008.09.014
[4]
CURI R, LAGRANHA C J, DOI S Q, et al. Molecular mechanisms of glutamine action[J]. Journal of Cellular Physiology, 2005, 204(2): 392-401. DOI:10.1002/(ISSN)1097-4652
[5]
SCHRÖDER J, WARDELMANN E, WINKLER W, et al. Glutamine dipeptide-supplemented parenteral nutrition reverses gut atrophy, disaccharidase enzyme activity, and absorption in rats[J]. Journal of Parenteral and Enteral Nutrition, 1995, 19(6): 502-506. DOI:10.1177/0148607195019006502
[6]
RENNIE M J, BOWTELL J L, BRUCE M, et al. Interaction between glutamine availability and metabolism of glycogen, tricarboxylic acid cycle intermediates and glutathione[J]. The Journal of Nutrition, 2001, 131(9): 2488S-2490S. DOI:10.1093/jn/131.9.2488S
[7]
LIN Y, XIAO Q Z. Dietary glutamine supplementation improves structure and function of intestine of juvenile Jian carp (Cyprinus carpio var. Jian)[J]. Aquaculture, 2006, 256(1/2/3/4): 389-394.
[8]
CHENG Z Y, BUENTELLO A, GATLIN Ⅲ D M. Effects of dietary arginine and glutamine on growth performance, immune responses and intestinal structure of red drum, Sciaenops ocellatus[J]. Aquaculture, 2011, 319(1/2): 247-252.
[9]
QIYOU X, QING Z, HONG X, et al. Dietary glutamine supplementation improves growth performance and intestinal digestion/absorption ability in young hybrid sturgeon (Acipenser schrenckii ♀×Huso dauricus)[J]. Journal of Applied Ichthyology, 2011, 27(2): 721-726. DOI:10.1111/j.1439-0426.2011.01710.x
[10]
POHLENZ C, BUENTELLO A, CRISCITIELLO M F, et al. Synergies between vaccination and dietary arginine and glutamine supplementation improve the immune response of channel catfish against Edwardsiella ictaluri[J]. Fish & Shellfish Immunology, 2012, 33(3): 543-551.
[11]
ZHANG K K, MAI K S, XU W, et al. Effects of dietary arginine and glutamine on growth performance, nonspecific immunity, and disease resistance in relation to arginine catabolism in juvenile turbot (Scophthalmus maximus L.)[J]. Aquaculture, 2017, 468: 246-254. DOI:10.1016/j.aquaculture.2016.10.021
[12]
BRITO G A C, CARNEIRO-FILHO B, ORIÁ R B, et al. Clostridium difficile toxin A induces intestinal epithelial cell apoptosis and damage:role of Gln and Ala-Gln in toxin A effects[J]. Digestive Diseases and Sciences, 2005, 50(7): 1271-1278. DOI:10.1007/s10620-005-2771-x
[13]
农业部渔业渔政管理局. 2017中国渔业统计年鉴[M]. 北京: 中国农业出版社, 2017.
[14]
JIANG J, XU S X, FENG L, et al. Lysine and methionine supplementation ameliorates high inclusion of soybean meal inducing intestinal oxidative injury and digestive and antioxidant capacity decrease of yellow catfish[J]. Fish Physiology and Biochemistry, 2018, 44(1): 319-328.
[15]
SONG Y F, LUO Z, PAN Y X, et al. Three unsaturated fatty acid biosynthesis-related genes in yellow catfish Pelteobagrus fulvidraco:molecular characterization, tissue expression and transcriptional regulation by leptin[J]. Gene, 2015, 563(1): 1-9.
[16]
LUO Z, WEI C C, YE H M. Effect of dietary choline levels on growth performance, lipid deposition and metabolism in juvenile yellow catfish Pelteobagrus fulvidraco[J]. Comparative Biochemistry and Physiology Part B:Biochemistry and Molecular Biology, 2016, 202: 1-7. DOI:10.1016/j.cbpb.2016.07.005
[17]
CHEN G H, HOGSTRAND C, LUO Z, et al. Dietary zinc addition influenced zinc and lipid deposition in the fore-and mid-intestine of juvenile yellow catfish Pelteobagrus fulvidraco[J]. British Journal of Nurtrition, 2017, 118(8): 570-579. DOI:10.1017/S0007114517002446
[18]
LI M, CHEN L Q, QIN J G, et al. Growth performance, antioxidant status and immune response in darkbarbel catfish Pelteobagrus vachelli fed different PUFA/vitamin E dietary levels and exposed to high or low ammonia[J]. Aquaculture, 2013, 406.
[19]
AOAC.Official methods of analysis of AOAC International[S].Gaithersburg, Maryland: Association of Official Analytical Chemists, 2000.
[20]
叶应妩, 王毓三, 申子瑜. 全国临床检验操作规程[M]. 3版.南京: 东南大学出版社, 2006: 595-606.
[21]
BERGMEYER H U. Methods of enzymatic analysis[M]. New York: Academic Press, 1985: 454-461.
[22]
IP Y K, LEONG M W, SIM M Y, et al. Chronic and acute ammonia toxicity in mudskippers, Periophthalmodon schlosseri and Boleophthalmus boddaerti:brain ammonia and glutamine contents, and effects of methionine sulfoximine and MK801[J]. Journal of Experimental Biology, 2005, 208(10): 1993-2004. DOI:10.1242/jeb.01586
[23]
MILLWARD D J, JEPSON M M, OMER A. Muscle glutamine concentration and protein turnover in vivo in malnutrition and in endotoxemia[J]. Metabolism, 1989, 38(Suppl.1): 6-13.
[24]
CHEN X M, GUO G L, SUN L, et al. Effects of Ala-Gln feeding strategies on growth, metabolism, and crowding stress resistance of juvenile Cyprinus carpio var. Jian[J]. Fish & Shellfish Immunology.
[25]
DING Z K, LI W F, HUANG J H, et al. Dietary alanyl-glutamine and vitamin E supplements could considerably promote the expression of GPx and PPARα genes, antioxidation, feed utilization, growth, and improve composition of juvenile cobia[J]. Aquaculture, 2017, 470: 95-102. DOI:10.1016/j.aquaculture.2016.12.015
[26]
ROGERO M M, TIRAPEGUI J, PEDROSA R G, et al. Effect of alanyl-glutamine supplementation on plasma and tissue glutamine concentrations in rats submitted to exhaustive exercise[J]. Nutrition, 2006, 22(5): 564-571. DOI:10.1016/j.nut.2005.11.002
[27]
ANDERSON P M, BRODERIUS M A, FONG K C, et al. Glutamine synthetase expression in liver, muscle, stomach and intestine of Bostrichthys sinensis in response to exposure to a high exogenous ammonia concentration[J]. Journal of Experimental Biology, 2002, 205: 2053-2065.
[28]
POHLENZ C, BUENTELLO A, BAKKE A M, et al. Free dietary glutamine improves intestinal morphology and increases enterocyte migration rates, but has limited effects on plasma amino acid profile and growth performance of channel catfish Ictalurus punctatus[J]. Aquaculture, 2012, 370-371: 32-39. DOI:10.1016/j.aquaculture.2012.10.002
[29]
HAN Y Z, KOSHIO S, JIANG Z Q, et al. Interactive effects of dietary taurine and glutamine on growth performance, blood parameters and oxidative status of Japanese flounder Paralichthys olivaceus[J]. Aquaculture, 2014, 434: 348-354. DOI:10.1016/j.aquaculture.2014.08.036
[30]
COUTINHO F, CASTRO C, RUFINO-PALOMARES E, et al. Dietary glutamine supplementation effects on amino acid metabolism, intestinal nutrient absorption capacity and antioxidant response of gilthead sea bream (Sparus aurata) juveniles[J]. Comparative Biochemistry and Physiology Part A:Molecular & Integrative Physiology, 2016, 191: 9-17.
[31]
GU M, BAI N, XU B Y, et al. Protective effect of glutamine and arginine against soybean meal-induced enteritis in the juvenile turbot (Scophthalmus maximus)[J]. Fish & Shellfish Immunology, 2017, 70: 95-105.
[32]
LIU J W, MAI K S, XU W, et al. Effects of dietary glutamine on survival, growth performance, activities of digestive enzyme, antioxidant status and hypoxia stress resistance of half-smooth tongue sole (Cynoglossus semilaevis Günther) post larvae[J]. Aquaculture, 2015, 446: 48-56. DOI:10.1016/j.aquaculture.2015.04.012
[33]
CHEN J, ZHOU X Q, FENG L, et al. Effects of glutamine on hydrogen peroxide-induced oxidative damage in intestinal epithelial cells of Jian carp (Cyprinus carpio var. Jian)[J]. Aquaculture, 2009, 288(3/4): 285-289.
[34]
LUO M H, BAZARGAN N, GRIFFITH D P, et al. Metabolic effects of enteral versus parenteral alanyl-glutamine dipeptide administration in critically ill patients receiving enteral feeding:a pilot study[J]. Clinical Nutrition, 2008, 27(2): 297-306. DOI:10.1016/j.clnu.2007.12.003
[35]
DOGUET F, TAMION F, LE GUILLOU V, et al. Albumin limits mesenteric endothelial dysfunction and inflammatory response in cardiopulmonary bypass[J]. Artificial Organs, 2012, 36(11): 962-971. DOI:10.1111/aor.2012.36.issue-11
[36]
FLAJNIK M F, KASAHARA M. Origin and evolution of the adaptive immune system:genetic events and selective pressures[J]. Nature Reviews Genetics, 2010, 11(1): 47-59. DOI:10.1038/nrg2703
[37]
CHEN H Y, MILLER P S, LEWIS A J, et al. Changes in plasma urea concentration can be used to determine protein requirements of two populations of pigs with different protein accretion rates[J]. Journal of Animal Science, 1995, 73(9): 2631-2639. DOI:10.2527/1995.7392631x
[38]
SAURABH S, SAHOO P K. Lysozyme:an important defence molecule of fish innate immune system[J]. Aquaculture Research, 2008, 39(3): 223-239.
[39]
BARTELL S M, BATAL A B. The effect of supplemental glutamine on growth performance, development of the gastrointestinal tract, and humoral immune response of broilers[J]. Poultry Science, 2007, 86(9): 1940-1947. DOI:10.1093/ps/86.9.1940
[40]
SHAH N J, NEEB H, KIRCHEIS G, et al. Quantitative cerebral water content mapping in hepatic encephalopathy[J]. Neuroimage, 2008, 41(3): 706-717. DOI:10.1016/j.neuroimage.2008.02.057
[41]
ROSE C. Increased extracellular brain glutamate in acute liver failure:decreased uptake or increased release?[J]. Metabolic Brain Disease, 2002, 17(4): 251-261. DOI:10.1023/A:1021945515514