L-Arginine/nitric oxide regulates skeletal muscle development via muscle fibre-specific nitric oxide/mTOR pathway in chickens  

作　　者：Ruxia Wang Kelin Li Li Sun Hongchao Jiao Yunlei Zhou Haifang Li Xiaojuan Wang Jingpeng Zhao Hai Lin 

机构地区：[1]Key Lab for Animal Biotechnology and Disease Control,Department of Animal Science,Shandong Agricultural University,Tai'an,271000,China [2]Institute of Biological Resources,Jiangxi Academy of Sciences,Nanchang,330096,China

出　　处：《Animal Nutrition》2022年第3期68-85,共18页动物营养（英文版）

基　　金：the Key Technologies Research and Development Programof China(2021YFD1300405);the Earmarked Fund for China Agriculture Research System(CARS-40-K09);National Natural Science Foundation of China(31772619);Key Technology Research and Development Program of Shandong Province(2019JZZY020602).

摘　　要：L-Arginine (L-Arg), the precursor of nitric oxide (NO), plays an important role in muscle function. Fasttwitchglycolytic fibres are more susceptible to age-related atrophy than slow-twitch oxidative fibres.The effect of L-Arg/NO on protein metabolism of fast- and slow-twitch muscle fibres was evaluated inchickens. In Exp. 1, 48 chicks at 1 day old were divided into 4 groups of 12 birds and subjected to 4treatments: basal diet without supplementation or supplemented with 1% L-Arg, and water supplementedwith or without L-nitro-arginine methyl ester (L-NAME, 18.5 mM). In Exp. 2, 48 chicks weredivided into 4 groups of 12 birds fed with the basal diet and subjected to the following treatments: tapwater (control), tap water supplemented with L-NAME (18.5 mM), or molsidomine (MS, 0.1 mM), or18.5 mM L-NAME t 0.1 mM MS (NAMS). The regulatory effect of L-Arg/NO was further investigatedin vitro with myoblasts obtained from chicken embryo pectoralis major (PM) and biceps femoris (BF).In vivo, dietary L-Arg supplementation increased breast (t14.94%, P < 0.05) and thigh muscle mass(t23.40%, P < 0.05);whereas, MS treatment had no detectable influence. However, L-NAME treatmentblocked the beneficial influence of L-Arg on muscle development. L-Arg decreased (P < 0.05) proteinsynthesis rate, phosphorylated mTOR and ribosomal protein S6 kinase beta-1 (p70S6K) levels in breastmuscle, which was recovered by L-NAME treatment. In vitro, L-Arg or sodium nitroprusside (SNP)reduced protein synthesis rate, suppressed phosphorylated mTOR/p70S6K and decreased atrogin-1 andmuscle RING finger 1 (MuRF1) in myoblasts from PM muscle (P < 0.05). L-NAME abolished the inhibitoryeffect of L-Arg on protein synthesis and the mTOR/p70S6K pathway. However, myoblasts from BF muscleshowed the weak influence. Moreover, blocking the mTOR/p70S6K pathway with rapamycin suppressedprotein synthesis of the 2 types of myoblasts;whereas, the protein expression of atrogin-1 and MuRF1levels were restricted only in myoblasts from PM muscle. In conclusion, L-Arg/NO/mTO

关 键 词：Muscle fibre L-ARGININE Nitric oxide/mTOR/p70S6K ATROGIN-1 Muscle RING finger 1 CHICKEN 

分 类 号：S831.5[农业科学—畜牧学]