Conjugated linoleic acid affects lipid composition, metabolism, and gene expression in Gilthead sea bream (Sparus aurata L)
Conjugated linoleic acid affects lipid composition, metabolism, and gene expression in Gilthead sea bream (Sparus aurata L)
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DOI：
10.1093/jn/137.6.1363
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发表时间：
2007-06-01
影响因子：
4.2
通讯作者：
Bautista, Jose M.
中科院分区：
文献类型：
--
作者：
Diez, Amalia;Menoyo, David;Bautista, Jose M.
为了最大限度地提高鱼的生长，养殖鱼被喂食高脂肪饲料，这会导致高组织脂质浓度，从而影响鱼的质量。哺乳动物摄入共轭亚油酸（CLA）可减少体脂，本研究旨在确定共轭亚油酸对海鲷的生长、组成和餐后代谢变量的影响。鱼分别饲喂3种饲料，其中蛋白质含量为48 g/100 g，脂肪含量为24 g/100 g，鱼油中添加0（对照）、2和4%的CLA，为期12周。采食量、特定生长率、体脂总量和循环生长肌动素浓度均低于对照组。添加2% CLA的鱼的饲料效率高于对照组。饲料中添加4% CLA的鱼肝脏甘油三酯浓度高于对照组，而两种饲料中添加CLA的鱼肌肉甘油三酯浓度低于对照组。肝脏脂肪酰基去饱和酶和延长酶mRNA水平低于对照组。在最后一餐后6 h（而不是24 h）观察到对照组和喂食cla的鱼之间的代谢差异，包括餐后循环甘油三酯浓度低于对照组，肝脏酰基辅酶a氧化酶较高，l- 3-羟基酰基辅酶a脱氢酶活性低于对照组。饲粮中添加CLA对肝脏脂肪酸合成酶和苹果酸酶等参与脂肪生成的酶没有影响，但在饲喂后24 h降低葡萄糖6-磷酸清氢酶活性，而在饲喂后6 h没有影响。这些数据表明，摄入CLA对海鲷肝脏脂肪生成的影响很小，它将饲料中的脂肪从脂肪组织转运到肝脏，并将肝脏线粒体转变为过氧化物酶体b氧化。
To maximize growth, farmed fish are fed high-fat diets, which can lead to high tissue lipid concentrations that have an impact on quality. The intake of conjugated linoleic acid (CLA) reduces body fat in mammals and this study was undertaken to determine the effects of dietary CLA on growth, composition, and postprandial metabolic variables in sea bream. Fish were fed 3 diets containing 48 g/100 g protein and 24 g/100 g fat, including fish oil supplemented with 0 (control), 2, or 4% CLA for 12 wk. Feed intake, specific growth rate, total body fat, and circulating somatolactin concentration were lower in fish fed CLA than in controls. Feed efficiency was greater in fish fed 2% CLA than in controls. Liver triglyceride concentrations were higher in fish fed 4% CLA and muscle triglyceride concentrations were lower in fish fed both CLA diets than in controls. Hepatic fatty acyl desaturase and elongase mRNA levels in fish fed CLA were lower than in controls. Metabolic differences between controls and CLA-fed fish were observed at 6 h but not at 24 h after the last meal, including lower postprandial circulating triglyceride concentrations, higher hepatic acyl-CoA-oxidase, and lower L-3-hydroxyacyl-CoA dehydrogenase activities in CLA-fed fish than in controls. Dietary CLA did not affect enzymes involved in lipogenesis including hepatic fatty acid synthase and malic enzyme, but it decreased glucose 6-phosphate clehydrogenase activity at 24 h, but not at 6 h after feeding. The data suggest that CLA intake in sea bream has little effect on hepatic lipogenesis, channels dietary lipid from adipose tissue to the liver, and switches hepatic mitochondrial to peroxisomal B-oxidation.