Fish oil can not only provide energy for the growth and development of fish, but also constitute a variety of tissue and cellular structural components of fish. However, fish oil is easily oxidized in the process of feed processing, treatment and storage, which reduces the feed quality and threatens the health of fish. Therefore, the purpose of this study was to investigate the effects of different degrees of oxidation of fish oil in feed on fatty acid composition and lipid metabolism in hepatopancreas of Rhynchocypris lagowski Dybowski. Five diets containing five oxidation levels (0, 100, 200, 300 and 400 meq/kg) of fish oil were formulated and fed to 525 healthy R. lagowski (4.48 ± 0.14 g) that were randomly divided into 15 glass aquariums. After 8 weeks, hepatopancreas samples were taken for fatty acid composition, and biochemical analysis. The results showed that the content of Polyunsaturated fatty acid (PUFA) in muscle of R. lagowski increased significantly with the increase of oxidation degree of fish oil (P < 0.05), but there were no changes in Saturated fatty acid (SFA), Monounsaturated fatty acid (MUFA), EPA (C20:5n3), and ∑n-6 (P>0.05). Compared with the control group, the contents of SFA, MUFA and EPA in hepatopancreas were significantly increased (P < 0.05), while DHA (C22:6n3), ∑n-3, ∑n-6, and PUFA were decreased (P < 0.05). Feeding with OFO increased hepatopancreas total cholesterol (TC), triacylglycerol (TG), HDL/LDL ratio, FAS, and ACCα that involved in lipid synthesis enzymes (P < 0.05), while reduced liver esterase (HL), fatty acyl-CoA synthetase (ACS), carnitine palmitoyltransferase (CPT-1) and hormone-sensitive triglyceride lipase α (HSLα) enzyme activity and gene expression that associated with lipid decomposition (P < 0.05). It is suggested that the adverse effects of dietary oxidized oil may be achieved by promoting fatty acid synthesis, inhibiting fatty acid oxidation, increasing fatty acid uptake by hepatopancreas and reducing the ability of TG to transport from hepatopancreas to extrahepatic tissues, thus inducing fat accumulation in hepatopancreatic cells and further affecting lipid metabolism in hepatopancreas.

鱼油不仅可以为鱼的生长和发育提供能量，而且可以构成鱼的各种组织和细胞结构成分。但是，鱼油在饲料加工，处理和储存过程中容易被氧化，从而降低了饲料质量，威胁了鱼类的健康。因此，本研究的目的是研究饲料中鱼油的不同程度的氧化作用对拉格氏丝藻的肝胰脏脂肪酸组成和脂质代谢的影响。配制了包含五种氧化水平（0、100、200、300和400毫克当量/千克）鱼油的五种日粮，并喂给525名健康的拉格夫斯基（4.48±0.14 g），随机分为15个玻璃水族箱。8周后，取肝胰腺样品进行脂肪酸组成和生化分析。结果表明，随着鱼油氧化度的增加，拉格夫斯基肌肉中多不饱和脂肪酸（PUFA）的含量明显增加（P <0.05），而单不饱和脂肪酸的饱和脂肪酸（SFA）没有变化。脂肪酸（MUFA），EPA（C20：5n3）和∑n-6（P> 0.05）。与对照组相比，肝胰脏中SFA，MUFA和EPA的含量显着增加（P <0.05），而DHA（C22：6n3），∑n-3，∑n-6和PUFA的含量降低（P<0.05）。饲喂OFO可增加参与脂质合成酶的肝胰腺总胆固醇（TC），三酰甘油（TG），HDL / LDL比，FAS和ACCα（P <0.05），同时降低肝酯酶（HL），脂肪酰基辅酶A合成酶（ACS），肉碱棕榈酰转移酶（CPT-1）和激素敏感性甘油三脂脂肪酶α（HSLα）的酶活性以及与脂质分解相关的基因表达（P<0.05）。建议通过促进脂肪酸合成，抑制脂肪酸氧化，增加肝胰腺对脂肪酸的摄取以及降低TG从肝胰腺向肝外组织转运的能力，从而诱导脂肪的积累，来实现膳食氧化油的不良作用。肝胰腺细胞并进一步影响肝胰腺的脂质代谢。