An eight weeks feeding trial was conducted to investigate the effects of dietary lipid levels on growth performance, lipid metabolism and immune response of Japanese seabass (Lateolabrax japonicus). Five diets were formulated with gradient dietary lipid levels (79.6, 104.4, 129.1, 154.9 and 178.6 g kg⁻¹). Results revealed that growth and feed utilization of fish were significantly lower in group L178.6 than other groups (p < 0.05). Lipid accumulation in whole body, muscle and intraperitoneal were increased with increasing dietary lipid levels. The mRNA levels of adipose triglyceride lipase, carnitine palmitoyl transferase 1, acetyl CoA carboxylase, cholesterol 7 alpha‐hydroxylase and retinoid X receptor in liver were also increased with increasing dietary lipid levels (p < 0.05). The mRNA levels of apolipoprotein A1 and peroxisome proliferator activating receptor α were higher in fish fed L178.6 than those fed other diets. Oxidative stress in plasma and liver were induced when dietary lipid exceed 154.9 g kg⁻¹. L154.9 and L178.6 significantly increased the inflammatory related gene expression of fish. These results suggested that high‐fat diet impaired the growth performance and induced lipid accumulation, inflammation and apoptosis of Japanese seabass. The suitable dietary lipid level of Japanese seabass may not exceed 129.1 g kg⁻¹.

中文翻译：

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膳食脂质水平影响日本鲈鱼的生长性能，脂质蓄积，炎症反应和细胞凋亡

进行了为期八周的喂养试验，以研究日粮脂质水平对日本鲈鱼（Lateolabrax japonicus）的生长性能，脂质代谢和免疫反应的影响。配制了五种日粮中的脂质血脂水平为渐变（79.6、104.4、129.1、154.9和178.6 g kg ^-1）。结果显示，L178.6组的鱼类生长和饲料利用率显着低于其他组（p  <0.05）。随着饮食中脂质水平的增加，全身，肌肉和腹膜内的脂质蓄积增加。脂肪甘油三酸酯脂肪酶，肉碱棕榈酰转移酶1，乙酰辅酶A羧化酶，胆固醇7α的mRNA水平。-羟化酶和类视黄醇X受体在肝脏也与增加膳食脂质水平（增加的p  <0.05）。饲喂L178.6的鱼中载脂蛋白A1和过氧化物酶体增殖物激活受体α的mRNA水平高于饲喂其他日粮的鱼。当饮食脂质超过154.9 g kg ^-1时，会诱发血浆和肝脏的氧化应激。L154.9和L178.6显着增加了鱼的炎症相关基因表达。这些结果表明，高脂饮食会损害日本鲈鱼的生长性能，并引起脂质堆积，炎症和细胞凋亡。日本鲈鱼的适宜饮食脂质含量不得超过129.1 g kg ^-1。