Influence of conjugated linoleic acid (CLA) or tetradecylthioacetic acid (TTA) on growth, lipid composition, fatty acid metabolism and lipid gene expression of rainbow trout (Oncorhynchus mykiss L.)
Influence of conjugated linoleic acid (CLA) or tetradecylthioacetic acid (TTA) on growth, lipid composition, fatty acid metabolism and lipid gene expression of rainbow trout (Oncorhynchus mykiss L.)
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DOI：
10.1016/j.aquaculture.2007.06.033
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发表时间：
2007-11-26
期刊：
影响因子：
4.5
通讯作者：
Tocher, Douglas R.
中科院分区：
文献类型：
--
作者：
Kennedy, Sean R.;Bickerdike, Ralph;Tocher, Douglas R.
我们的目的是验证共轭亚油酸(CLA)和/或十四烷基硫代乙酸(TTA)可能通过降低鱼肉或内脏的脂肪含量、增加有益脂肪酸水平(包括CLA或TTA本身的积累)而对虹鱼(Oncorhynchus Mykises)的营养品质产生有利影响的假设。本研究的具体目的是确定CLA和TTA对海水养殖商品规格鲑鱼生长性能、脂肪和脂肪酸代谢以及选定基因表达的影响。用含有0.5%或1%共轭亚油酸或0.5%TTA的鱼粉和鱼油饲料喂养鲑鱼8周。测定了添加脂肪酸对肉、肝生长、饲料效率、脂肪含量、种类组成和脂肪酸组成、肝脏高度不饱和脂肪酸合成、肝脏和肌肉中脂肪酸氧化关键酶活性以及肉碱棕榈酰转胺酶(CPT-I)、脂肪酰脱饱和酶和伸长酶基因表达的影响。两种功能性脂肪酸对生长参数、条件因子、内脏和肝体指数以及鱼片颜色都没有任何影响，并且在任何处理中都没有死亡。日粮中CLA和TTA均能降低肝脏脂肪含量，但对肝脏和肉脂组成无显著影响。CLA和TTA都被结合到组织脂中，与肝脏相比，在肉类中发现的比例更高。此外，CLA和TTA均能促进肝微粒体合成己烯脂肪酸，且两种功能脂肪酸均可提高n-3脂肪酸在肝脏中的比例，这主要是由于增加了20：5n-3和22：6n-3。但添加CLA或TTA的鱼，脂肪酰基Delta 6脱饱和酶的表达显著降低，而多不饱和脂肪酸伸长酶的表达显著增加，1%CLA的鱼体中PUFA伸长酶的表达显著增加。TTA能提高肝脏和红肌中CPT-I的活性，在较高的饲料包涵体水平下，TTA和CLA能提高肝脏和红肌中的酰基辅酶A氧化酶活性。CLA和TTA均能显著增加白肌中CPT-I的表达。结果表明，共轭亚油酸和TTA对脂类代谢均有影响，部分支持上述假设。虽然CLA或TTA不能提高生长参数、饲料转化率或潜在产量，但可以提高营养品质，而海鱼饲料中的CLA或TTA可以通过提供生物活性脂肪酸而有益于人类饲料，而对20：5N-3或22：6N-3水平没有不利影响。(C)2007年，爱思唯尔出版。
Our objective was to test the hypotheses that conjugated linoleic acid (CLA) and/or tetradecylthioacetic acid (TTA) would have beneficial effects on the nutritional quality of rainbow trout (Oncorhynchus mykiss) through decreased lipid content of flesh or viscera, and increased levels of beneficial fatty acids including accumulation of CLA or TTA themselves. The specific aims of this study were to determine the effects of CLA and TTA on growth performance, lipid and fatty acid metabolism, and selected gene expression in commercial sized trout grown in seawater. Trout were fed for eight weeks on fish meal and fish oil diets containing either 0.5% or 1% CLA, or 0.5% TTA. The effects of the supplemented fatty acids on growth, feed efficiency, lipid contents, class compositions and fatty acid compositions of flesh and liver were determined, along with liver highly unsaturated fatty acid synthesis, activities of key enzymes of fatty acid oxidation in liver and muscle, and expression of carnitine palmitoyl transfemse-I (CPT-I) and fatty acyl desaturase and elongase genes. Neither functional fatty acid had any effect on growth parameters, condition factor, viscero- and hepato-somatic indices or fillet colour, and there were no mortalities in any of the treatments. Dietary CLA, but not TTA, decreased the lipid content of liver, but neither fatty acid had any significant effect on lipid class compositions of liver and flesh. Both CLA and TTA were incorporated into tissue lipids, with higher percentages found in flesh compared to liver. In addition, production of hexaene fatty acid by liver microsomes was increased by dietary CLA or TTA, and both functional fatty acids increased the proportion of n - 3 fatty acids in liver mainly due to increased 20:5n - 3 and 22:6n - 3. However, the expression of fatty acyl Delta 6 desaturase was significantly lower in fish fed CLA or TTA, whereas the expression of PUFA elongase was increased, significantly so in fish fed 1% CLA. CPT-I activity was increased by TTA in liver and red muscle, and acyl CoA oxidase activity was increased by TTA in liver and CLA at the higher dietary inclusion level in red muscle. CPT-I expression in white muscle was significantly increased in fish fed both CLA and TTA. The results showed that both CLA and TTA had effects on lipid metabolism that partly support the hypotheses tested. Although CLA or TTA did not enhance growth parameters, feed conversion or potential yield, nutritional quality could be enhanced, and sea-run trout fed CLA or TTA could be beneficial in the human diet through provision of bioactive fatty acids, with no detrimental effects on 20:5n - 3 or 22:6n - 3 levels. (c) 2007 Published by Elsevier B.V.