高碳水化合物饲料添加精氨酸对杂交鳢的生长性能、抗氧化酶活性、肝脏免疫反应及糖代谢相关基因的影响

Effects of high carbohydrate diets supplemented with arginine on growth performance,antioxidant activity,immune response and genes related to glucose metabolism in hybrid snakehead[Channa maculata(♀)×C.argus(♂)]

为研究高碳水化合物饲料添加精氨酸对杂交鳢幼鱼生长性能、体组成、血浆生化、抗氧化酶活性、葡萄糖代谢以及免疫相关基因的影响。实验选取初始体重(22.02±0.02)g的杂交鳢450尾,随机分为3个组,每组3个重复,每个重复50尾鱼,分别投喂碳水化合物水平为21.34%(低,LC组)、27.45%(高,HC组)和27.38%(添加Arg,Arg组)的3种实验饲料饲喂8周。结果显示,与低碳水化合物饲料(LC组)相比,高碳水化合物饲料(HC组)显著降低杂交鳢增重率(WGR)、特定生长率(SGR)和蛋白质沉积率(PDR),饲料系数(FCR)提高,精氨酸组(Arg组)的添加显著降低了FCR,显著提高了WGR、SGR、PDR、全鱼粗蛋白和血浆蛋白含量。与LC组相比,HC组血浆和肝脏丙二醛(MDA)含量和肝脏肿瘤坏死因子-α(TNF-α)表达量显著升高,肠道总抗氧化能力(T-AOC)、过氧化物酶(POD)、谷胱甘肽过氧化物酶(GSH-Px),以及肝脏POD、GSH-Px活性、肝脏磷酸烯醇丙酮酸羧激酶(PEPCK)、葡萄糖转运蛋白-2(GLUT2)、转化生长因子(TGF-β)和热休克蛋白70(HSP70)基因表达量显著下降。氧化应激和肝脏炎症提示,喂食高碳水化合物饲料的杂交鳢患有肝脏疾病。饲喂添加Arg的饲料可以通过减少MDA的含量和增强T-AOC、POD、GSH-Px和超氧化物歧化酶(SOD)活性来增强肝脏的抗氧化能力。与HC组饲料相比,饲喂添加Arg饲料的杂交鳢促炎因子白细胞介素-8(IL-8)、白细胞介素-1β(IL-1β)和TNF-α的表达量显著降低,抗炎因子TGF-β、HSP70和热休克蛋白90(HSP90)表达量显著升高,提示饲料补充Arg后肝脏炎症反应得到缓解。研究表明,Arg通过上调肝脏胰岛素相关基因蛋白激酶B(AKT)、胰岛素受体底物-1(IRS-1)、磷脂酰肌醇-3激酶(PI3K)和葡萄糖代谢相关基因PEPCK、葡萄糖-6磷酸酶(G6P)和丙酮酸激酶(PK)的表达来促进胰岛素的产生和糖原分解,从而调节鱼类的肝糖代谢。综上,高碳水化合物饲料可诱发杂交鳢的氧化应激和炎症,而补充Arg可增强抗氧化活性,缓解炎症,促进葡萄糖代谢。

This experiment investigated the effects of high carbohydrate diets supplemented with arginine on growth performance,body composition,plasma biochemistry,antioxidant activity,glucose metabolism and immune-related genes in juvenile hybrid snakehead[Channa maculata(♀)×C.argus(♂)].The 450 hybrid snakehead with initial body weight of(22.02±0.02)g were randomly divided into three groups with three replicates of 50 fishes each and fed three experimental diets with carbohydrate levels of 21.34%,27.45%and 27.38%,respectively,and were recorded as LC,HC and Arg groups for eight weeks.The results showed that compared with lowcarbohydrate diet(LC group),high-carbohydrate diet(HC group)significantly decreased the weight gain rate(WGR),specific growth rate(SGR),and protein deposition rate(PDR),and increased the feed ratio(FCR).The addition of arginine group(Arg group)significantly decreased FCR.Significantly improved the WGR,SGR,PDR,whole fish plasma protein and crude protein content.Compared with the LC group,the plasma and liver malondialdehyde(MDA)content and liver tumor necrosis factor-α(TNF-α)expression were significantly increased in the HC group.Intestinal total antioxidant capacity(T-AOC)and peroxidase(POD)and glutathione peroxidase(GSHPx)and liver POD and GSH-Px activity,hepatic phosphoenolpyruvate carboxylase(PEPCK),glucose transporter protein-2(GLUT-2),transforming growth factor(TGF-β)and heat shock protein 70(HSP70)gene expression quantity dropped significantly.Oxidative stress and liver inflammation suggested liver disease in hybrid snakehead fed a high carbohydrate diet.Feeding the diet supplemented with Arg could enhance the antioxidant capacity of the liver by reducing the content of MDA and strengthening the activities of T-AOC,POD,GSH-Px and superoxide dismutase(SOD).Compared with the HC group,the expressions of pro-inflammatory factors interleukin-8(IL-8),interleukin-1β(IL-1β)and tumor necrosis factor-α(TNF-α)were significantly decreased,and the expressions of anti-inflammatory factors TGF-β,HSP70 and heat shock protein 90(HSP90)were significantly increased in C.maculata(♀)×C.argus(♂)fed with Arg diet.These results suggest the liver inflammatory response was relieved after dietary supplementation with Arg.Studies have shown that,Arg promoted insulin production and glycogenolysis by up-regulating the expression of insulin-related genes protein kinase B(AKT),insulin receptor subset-1(IRS-1)and phosphatidylinositol-3 kinase(PI3K)and glucose metabolism-related genes PEPCK,glucose-6 phosphatase(G6P)and pyruvate kinase(PK)in the liver.Thus,it regulates hepatic glucose metabolism in fish.In conclusion,a high carbohydrate(HC group)diet induced oxidative stress and inflammation in C.maculata(♀)×C.argus(♂),while Arg supplementation enhanced antioxidant activity,alleviated inflammation,and promoted glucose metabolism.