title: Free Amino Acid Profile and Expression of Genes Implicated in Protein Metabolism in Skeletal Muscle of Growing Pigs Fed Low-Protein Diets Supplemented with Branched-Chain Amino Acids.
abstract: Revealing the expression patterns of genes involved in protein metabolism as affected by diets would be useful for further clarifying the importance of the balance among the branched-chain amino acids (BCAAs), which include leucine (Leu), isoleucine (Ile), and valine (Val). Therefore, we used growing pigs to explore the effects of different dietary BCAA ratios on muscle protein metabolism. The Leu:Ile:Val ratio was 1:0.51:0.63 (20% crude protein, CP), 1:1:1 (17% CP), 1:0.75:0.75 (17% CP), 1:0.51:0.63 (17% CP), and 1:0.25:0.25 (17% CP), respectively. Results showed that compared with the control group, low-protein diets with the BCAA ratio ranging from 1:0.75:0.75 to 1:0.25:0.25 elevated muscle free amino acid (AA) concentrations and AA transporter expression, significantly activated the mammalian target of rapamycin complex 1 pathway, and decreased serum urea nitrogen content and the mRNA expression of genes related to muscle protein degradation (P < 0.05). In conclusion, these results indicated that maintaining the dietary Leu:Ile:Val ratio within 1:0.25:0.25-1:0.75:0.75 in low-protein diets (17% CP) would facilitate the absorption and utilization of free AA and result in improved protein metabolism and muscle growth.
authors.affiliation: Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences ; Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production; Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Changsha 410125, China.|University of Chinese Academy of Sciences , Beijing 100039, China.
authors.forename: Yehui
authors.initials: Y
authors.lastname: Duan
authors.affiliation: Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences ; Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production; Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Changsha 410125, China.|University of Chinese Academy of Sciences , Beijing 100039, China.
authors.forename: Qiuping
authors.initials: Q
authors.lastname: Guo
authors.affiliation: Laboratory of Animal Nutrition and Human Health, School of Biology, Hunan Normal University , Changsha, Hunan 410018, China.
authors.forename: Chaoyue
authors.initials: C
authors.lastname: Wen
authors.affiliation: Laboratory of Animal Nutrition and Human Health, School of Biology, Hunan Normal University , Changsha, Hunan 410018, China.
authors.forename: Wenlong
authors.initials: W
authors.lastname: Wang
authors.affiliation: Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences ; Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production; Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Changsha 410125, China.|University of Chinese Academy of Sciences , Beijing 100039, China.
authors.forename: Yinghui
authors.initials: Y
authors.lastname: Li
authors.affiliation: Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences ; Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production; Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Changsha 410125, China.
authors.forename: Bie
authors.initials: B
authors.lastname: Tan
authors.affiliation: Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences ; Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production; Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Changsha 410125, China.|Hunan Co-Innovation Center of Animal Production Safety, CICAPS; Hunan Collaborative Innovation Center for Utilization of Botanical Functional Ingredients , Changsha 410128, China.
authors.forename: Fengna
authors.initials: F
authors.lastname: Li
authors.affiliation: Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences ; Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production; Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Changsha 410125, China.|Laboratory of Animal Nutrition and Human Health, School of Biology, Hunan Normal University , Changsha, Hunan 410018, China.
authors.forename: Yulong
authors.initials: Y
authors.lastname: Yin
mesh_terms: D000596:Amino Acids / Q000737:chemistry / Q000378:metabolism*; D000597:Amino Acids, Branched-Chain / Q000378:metabolism*; D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D018753:Diet, Protein-Restricted; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism; D018482:Muscle, Skeletal / Q000737:chemistry / Q000378:metabolism*; D013552:Swine / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D000597:Amino Acids, Branched-Chain; D009124:Muscle Proteins
keywords: amino acid transceptor; branched-chain amino acid ratio; free amino acid; growing pig; low-protein diets; mTORC1 pathway