The involvement of dietary methionine in the lipid metabolism of Seriola dorsalis, at different levels of dietary methionine (Met), and low content of cholesterol was investigated. Four diets containing different Met levels and a low amount of cholesterol (0.23 g/kg diet) were prepared. One hundred and eighty juveniles (16.2 ± 1.5 g) were randomly distributed into each 12 500‐L ponds. After 60 days, the growth in weight (%) significantly increased following the Met supplementation, whereas SGR of all the experimental treatments was higher than the Basal Diet. The expression of the insulin‐like growth factor (IGF‐1) increased significantly (0.2‐fold) and was complemented by significant changes in Mat, BHMT and HMG‐CoA, for fish that were in the low and higher Met levels. The cholesterol content in the whole body and liver increased following methionine supplementation, similarly to that observed for crude lipids, in particular in the whole body and liver tissues. However, the relative amount of most fatty acids remained unchanged. Only the oleic acid increased at a higher amount of Met. Therefore, once the dietary requirement of methionine is met, the methionine is used to synthesize cholesterol. It is recommended to supply a higher amount of methionine to spare energy for growth.

中文翻译：

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饲喂不同水平的低蛋氨酸饮食蛋氨酸的黄尾，幼鱼的脂质代谢：对饲料配方的影响

饮食蛋氨酸参与背心血脂的脂质代谢，在饮食中蛋氨酸（Met）含量不同的情况下，胆固醇含量低。制备了四种含有不同Met水平和少量胆固醇（0.23 g / kg饮食）的饮食。将180个幼鱼（16.2±1.5 g）随机分配到每个12 500-L池塘中。60天后，补充Met后体重增加（％）显着增加，而所有实验治疗的SGR均高于基础饮食。对于Met水平较低和较高的鱼类，胰岛素样生长因子（IGF-1）的表达显着增加（0.2倍），并且通过Mat，BHMT和HMG-CoA的显着变化得到补充。补充蛋氨酸后，全身和肝脏中的胆固醇含量增加，与对粗脂质的观察到的相似，特别是在全身和肝脏组织中。但是，大多数脂肪酸的相对量保持不变。只有更高的Met量才增加油酸。因此，一旦满足了蛋氨酸的饮食需求，就可以使用蛋氨酸来合成胆固醇。建议提供更多量的蛋氨酸，以节省生长所需的能量。