Flesh Shear Force, Cooking Loss, Muscle Antioxidant Status and Relative Expression of Signaling Molecules (Nrf2, Keap1, TOR, and CK2) and Their Target Genes in Young Grass Carp (Ctenopharyngodon idella) Muscle Fed with Graded Levels of Choline.
Flesh Shear Force, Cooking Loss, Muscle Antioxidant Status and Relative Expression of Signaling Molecules (Nrf2, Keap1, TOR, and CK2) and Their Target Genes in Young Grass Carp (Ctenopharyngodon idella) Muscle Fed with Graded Levels of Choline.
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DOI：
10.1371/journal.pone.0142915
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Zhou XQ
中科院分区：
文献类型：
--
作者：
Zhao HF;Feng L;Jiang WD;Liu Y;Jiang J;Wu P;Zhao J;Kuang SY;Tang L;Tang WN;Zhang YA;Zhou XQ
六组草鱼（平均体重 266.9 ± 0.6 g）饲喂含有 197、385、770、1082、1436 和 1795 mg 胆碱/kg 的饲料，持续 8 周。适当添加胆碱可显着提高鱼苗的生长速度和幼草鱼肌肉营养成分（蛋白质、脂肪和氨基酸）的含量。此外，通过最佳膳食胆碱补充，肌肉羟脯氨酸浓度、乳酸含量和剪切力得到改善。然而，肌肉pH值、蒸煮损失和组织蛋白酶活性却呈现相反的趋势。此外，最佳膳食胆碱补充可减轻草鱼的肌肉氧化损伤。通过最佳膳食胆碱补充，肌肉抗氧化酶（过氧化氢酶和谷胱甘肽还原酶没有变化）活性和谷胱甘肽含量得到增强。肌肉烹饪损失与抗氧化酶活性和谷胱甘肽含量呈负相关。在基因水平上，这些抗氧化酶以及鱼肌肉中雷帕霉素、酪蛋白激酶2和NF-E2相关因子2转录物的靶标总是被合适的胆碱上调。然而，合适的胆碱显着降低了肌肉中 Kelch 样 ECH 相关蛋白 1a (Keap1a) 和 Kelch 样 ECH 相关蛋白 1b (Keap1b) mRNA 水平。总之，适当的膳食胆碱可以提高鱼肉质量，并且烹饪损失的减少是由于 Nrf2 信号传导可能调节的抗氧化状态升高所致。
Six groups of grass carp (average weight 266.9 ± 0.6 g) were fed diets containing 197, 385, 770, 1082, 1436 and 1795 mg choline/kg, for 8 weeks. Fish growth, and muscle nutrient (protein, fat and amino acid) content of young grass carp were significantly improved by appropriate dietary choline. Furthermore, muscle hydroxyproline concentration, lactate content and shear force were improved by optimum dietary choline supplementation. However, the muscle pH value, cooking loss and cathepsins activities showed an opposite trend. Additionally, optimum dietary choline supplementation attenuated muscle oxidative damage in grass carp. The muscle antioxidant enzyme (catalase and glutathione reductase did not change) activities and glutathione content were enhanced by optimum dietary choline supplementation. Muscle cooking loss was negatively correlated with antioxidant enzyme activities and glutathione content. At the gene level, these antioxidant enzymes, as well as the targets of rapamycin, casein kinase 2 and NF-E2-related factor 2 transcripts in fish muscle were always up-regulated by suitable choline. However, suitable choline significantly decreased Kelch-like ECH-associated protein 1 a (Keap1a) and Kelch-like ECH-associated protein 1 b (Keap1b) mRNA levels in muscle. In conclusion, suitable dietary choline enhanced fish flesh quality, and the decreased cooking loss was due to the elevated antioxidant status that may be regulated by Nrf2 signaling.