Short-term fasting increases skeletal muscle lipid content in association with enhanced mRNA levels of lipoprotein lipase 1 in lean juvenile red seabream (Pagrus major)
Short-term fasting increases skeletal muscle lipid content in association with enhanced mRNA levels of lipoprotein lipase 1 in lean juvenile red seabream (Pagrus major)
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DOI：
10.1016/j.aquaculture.2015.10.030
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发表时间：
2016-02-01
期刊：
影响因子：
4.5
通讯作者：
Ushio, Hideki
中科院分区：
文献类型：
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作者：
Kaneko, Gen;Shirakami, Hirohito;Ushio, Hideki
养殖鱼在运输或屠宰前通常会进行几天的短期禁食。这种干预减少了运输过程中的废物和氧气消耗，提高了肉质，但对它如何影响肌肉脂质含量知之甚少。更少的是知道野生捕捞的鱼，有时也禁食前屠宰。为了探讨短期禁食对肌肉脂质含量的影响，我们进行了三个禁食实验，成年，瘦少年，和脂肪少年红鲷（真鲷）。在第一个使用成人标本的实验中（在20摄氏度下进行），禁食10天导致脂蛋白脂酶1（LPL 1）、LPL 2和过氧化物酶体增殖物激活受体γ（PPAR）的肌肉mRNA水平增加2.3倍、7.8倍和3.7倍，（n=6）。这些基因都参与脂质积累。第二个实验在5组瘦幼红鲷[被认为是野生捕获的鱼; 19 ℃，除一组（n= 4）外，每组n=5]上进行。禁食5天显著增加肌肉脂质含量（湿重百分比）和LPL 1 mRNA水平分别高达2.2倍和11倍。LPL 2和PPAR的mRNA水平。可能由于它们的低表达水平而不能确定。肝脏中的脂质量（mg）在禁食期间减少了88%，而脂肪组织在禁食10天后明显消失。这些结果表明，从肝脏和脂肪组织的脂质动员预期肌肉利用脂质，导致在禁食期间肌肉脂质含量的反直觉增加。第三个实验是在7组多脂幼红鱼[视为养殖鱼; 20 ℃，除一组（n= 4）外，每组n= 5]上进行的。禁食10天不会增加肌肉脂质含量或LPL 1 mRNA水平。在实验过程中，肝脏中的脂质量减少，但脂肪组织中的脂质量没有减少。禁食10天是不够的，以诱导积极的脂质动员时，鱼禁食前喂得很好。与我们的预期相反，使用青少年样本的数据进行回归分析发现，LPL 1 mRNA水平和肝脏中的脂质量之间存在显着的负相关关系，这可能表明LPL 1 mRNA水平反映了组织对脂质的时间需求。总体而言，这些结果表明，短期禁食5天增加肌肉脂肪含量的野生捕获的瘦鱼可能通过LPL 1依赖的脂质转运mechanism.Statement的相关性：我们表明，短期禁食改善肉质。(C)2015 Elsevier B. V.版权所有。
Cultured fish are often subjected to short-term fasting for a few days prior to transport or slaughter. This intervention reduces waste and oxygen consumption during transport and improves flesh quality, but little is known about how it affects the muscle lipid content. Even less is known for wild-caught fish that are also sometimes fasted before slaughter. To investigate the effects of short-term fasting on muscle lipid content, we performed three fasting experiments using adult, lean juvenile, and fatty juvenile red seabream (Pagrus major). In the first experiment using adult specimens (performed at 20 degrees C), fasting for 10 days caused up to 2.3-, 7.8-, and 3.7-fold increases in muscle mRNA levels of lipoprotein lipase 1 (LPL1), LPL2, and peroxisome-proliferator-activated receptor gamma (PPAR.), respectively (n=6 each). These genes all participate in lipid accumulation. The second experiment was performed on 5 groups of lean juvenile red seabream [considered as wild-caught fish; 19 degrees C, n=5 each except for one group (n= 4)]. Fasting for 5 days significantly increased muscle lipid content (percentage of wet weight) and LPL1 mRNA levels up to 2.2- and 11-fold, respectively. The mRNA levels of LPL2 and PPAR. could not be determined possibly due to their low expression levels. The lipid amount (mg) in the liver decreased by 88% during fasting, whereas adipose tissue apparently disappeared after fasting for 10 days. These results suggest that lipid mobilization from liver and adipose tissue anticipated the muscular utilization of lipid, resulting in the counterintuitive increase in muscle lipid content during fasting. The third experiment was conducted on 7 groups of fatty juvenile red seabream [ considered as cultured fish; 20 degrees C, n= 5 each except for one group (n= 4)]. Fasting up to 10 days did not increase muscle lipid content or LPL1 mRNA levels. The lipid amount in the liver, but not in the adipose tissue, decreased during the experiment. Fasting for 10 days was not enough to induce active lipid mobilization when fish were well fed prior to fasting. Contrary to our expectations, regression analysis using data from juvenile specimens found a significant inverse relationship between LPL1 mRNA levels and lipid amount in the liver, which might indicate that LPL1 mRNA levels are a reflection of temporal tissue demand for lipids. Overall, these results suggest that short-term fasting for similar to 5 days increases muscle lipid content of wild-caught lean fish possibly by an LPL1-dependent lipid transport mechanism.Statement of relevance: We showed that short-term fasting improves flesh quality. (C) 2015 Elsevier B.V. All rights reserved.