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Zhou J, Tu J, Wang L, Yang L, Yang G, Zhao S, Zeng X, Qiao S. Free Amino Acid-Enriched Diets Containing Rapidly but Not Slowly Digested Carbohydrate Promote Amino Acid Absorption from Intestine and Net Fluxes across Skeletal Muscle of Pigs. J Nutr 2022; 152:2471-2482. [PMID: 36774113 DOI: 10.1093/jn/nxac165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 05/15/2022] [Accepted: 07/19/2022] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND The approach to matching appropriate carbohydrates alongside free amino acids to achieve optimal muscle growth remains unclear. OBJECTIVES We investigated whether the consumption of a diet containing rapidly digested carbohydrate and free amino acids can enhance intestinal absorption and muscular uptake of amino acids in pigs. METHOD Twelve barrows (28 kg; 11 wk old) with catheters installed in the portal vein, mesenteric vein, femoral artery, and femoral vein were randomly assigned to consume 1 of 2 free amino acid-enriched diets (3.34%) containing rapidly [waxy corn starch (WCS)] or slowly [pea starch (PS)] digested carbohydrate for 27 d. Blood was collected to determine the fluxes of plasma glucose and amino acids across the portal vein and the hindlimb muscle. Dietary in vitro carbohydrate digestive rates were also determined. Data were analyzed using repeated-measures (time × group) ANOVA. RESULTS Carbohydrate in vitro cumulative digestibility at 30 and 240 min was 69.00% and 95.25% for WCS and 23.25% and 81.15% for PS, respectively. The animal experiment presented WCS increased individual amino acids (lysine, 0.67 compared with 0.53 mmol/min; threonine, 0.40 compared with 0.29 mmol/min; isoleucine, 0.33 compared with 0.22 mmol/min; glutamate, 0.51 compared with 0.35 mmol/min; and proline, 0.51 compared with 0.27 mmol/min), essential amino acid (EAA; 3.26 compared with 2.65 mmol/min), and branched-chain amino acid (BCAA; 0.86 compared with 0.65 mmol/min) fluxes across the portal vein during 8 h postprandial, as well as individual amino acids (isoleucine, 0.08 compared with 0.02 mmol/min; leucine, 0.06 compared with 0.02 mmol/min; and glutamine, 0.44 compared with 0.25 mmol/min), EAA (0.50 compared with 0.21 mmol/min), and BCAA (0.17 compared with 0.06 mmol/min) net fluxes across the hindlimb muscle during 8 h postprandial compared with PS (P < 0.05). CONCLUSIONS A diet containing rapidly digested carbohydrate and free amino acids can promote intestinal absorption and net fluxes across hindlimb muscle of amino acids in pigs.
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Affiliation(s)
- Junyan Zhou
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture Feed Industry Centre, China Agricultural University, Beijing, PR China; Beijing Bio-feed additives Key Laboratory, Beijing, PR China
| | - Jiayu Tu
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture Feed Industry Centre, China Agricultural University, Beijing, PR China; Beijing Bio-feed additives Key Laboratory, Beijing, PR China
| | - Lu Wang
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture Feed Industry Centre, China Agricultural University, Beijing, PR China; Beijing Bio-feed additives Key Laboratory, Beijing, PR China
| | - Lijie Yang
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture Feed Industry Centre, China Agricultural University, Beijing, PR China; Beijing Bio-feed additives Key Laboratory, Beijing, PR China
| | - Guangxin Yang
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture Feed Industry Centre, China Agricultural University, Beijing, PR China; Beijing Bio-feed additives Key Laboratory, Beijing, PR China
| | - Shengjun Zhao
- Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan, PR China
| | - Xiangfang Zeng
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture Feed Industry Centre, China Agricultural University, Beijing, PR China; Beijing Bio-feed additives Key Laboratory, Beijing, PR China
| | - Shiyan Qiao
- State Key Laboratory of Animal Nutrition, Ministry of Agriculture Feed Industry Centre, China Agricultural University, Beijing, PR China; Beijing Bio-feed additives Key Laboratory, Beijing, PR China.
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Sun W, Li Y, Tang Z, Chen H, Wan K, An R, Wu L, Sun Z. Effects of adding sodium dichloroacetate to low-protein diets on nitrogen balance and amino acid metabolism in the portal-drained viscera and liver of pigs. J Anim Sci Biotechnol 2020; 11:36. [PMID: 32308979 PMCID: PMC7153232 DOI: 10.1186/s40104-020-00437-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 02/17/2020] [Indexed: 11/10/2022] Open
Abstract
Background Identifying regulatory measures to promote glucose oxidative metabolism while simultaneously reducing amino acid oxidative metabolism is one of the foremost challenges in formulating low-protein (LP) diets designed to reduce the excretion of nitrogen-containing substances known to be potential pollutants. In this study, we investigated the effects of adding sodium dichloroacetate (DCA) to a LP diet on nitrogen balance and amino acid metabolism in the portal-drained viscera (PDV) and liver of pigs.To measure nitrogen balance, 18 barrows (40 ± 1.0 kg) were fed one of three diets (n = 6 per group): 18% crude protein (CP, control), 13.5% CP (LP), and 13.5% CP + 100 mg DCA/kg dry matter (LP-DCA). To measure amino acid metabolism in the PDV and liver, 15 barrows (40 ± 1.0 kg) were randomly assigned to one of the three diets (n = 5 per group). Four essential amino acids (Lys, Met, Thr, and Trp) were added to the LP diets such that these had amino acid levels comparable to those of the control diet. Results The LP-DCA diet reduced nitrogen excretion in pigs relative to that of pigs fed the control diet (P < 0.05), without any negative effects on nitrogen retention (P > 0.05). There were no differences between the control and LP-DCA groups with respect to amino acid supply to the liver and extra-hepatic tissues in pigs (P > 0.05). The net release of ammonia into the portal vein and production rate of urea in the liver of pigs fed the LP-DCA diet was reduced relative to that of pigs fed the control and LP diets (P < 0.05). Conclusion The results indicated that addition of DCA to a LP diet can efficiently reduce nitrogen excretion in pigs and maximize the supply of amino acids to the liver and extra-hepatic tissues.
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Affiliation(s)
- Weizhong Sun
- 1Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, 400715 People's Republic of China
| | - Yunxia Li
- 2Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, 611130 People's Republic of China
| | - Zhiru Tang
- 1Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, 400715 People's Republic of China
| | - Huiyuan Chen
- 1Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, 400715 People's Republic of China
| | - Ke Wan
- 1Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, 400715 People's Republic of China
| | - Rui An
- 1Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, 400715 People's Republic of China
| | - Liuting Wu
- 1Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, 400715 People's Republic of China
| | - Zhihong Sun
- 1Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, 400715 People's Republic of China
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Li Y, Tang Z, Li T, Chen C, Huang F, Yang J, Xu Q, Zhen J, Wu Z, Li M, Sun J, Chen J, Zhang X, Wu L, An R, Zhao S, Jiang Q, Zhu W, Yin Y, Sun Z. Pyruvate is an effective substitute for glutamate in regulating porcine nitrogen excretion. J Anim Sci 2020; 96:3804-3814. [PMID: 30059979 DOI: 10.1093/jas/sky237] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Accepted: 06/10/2018] [Indexed: 01/22/2023] Open
Abstract
This study was performed to determine if pyruvate, which acts as a critical intermediate in energy metabolism, can substitute the role of glutamate as a metabolic fuel and effectively reduce nitrogen excretion in pigs. First, the experiment in vitro was carried out to investigate the effects of culturing porcine small intestinal epithelial cell line with pyruvate on the oxidation. Then, barrows weighing 40 kg were used in the experiment investigating the changes of nitrogen balance in response to addition of pyruvate to low-protein diets. Last, barrows (40 kg), which were surgically fitted with permanent catheters in the mesenteric vein, portal vein, hepatic vein, and carotid artery, were used to investigate the effects of supplementing low-protein diets with calcium pyruvate on the net portal fluxes of amino acids (AAs) and the consumption of AAs in the liver. The results showed that culturing cells with sodium pyruvate significantly reduced the number of glutamate oxidation (P < 0.05). Addition of calcium pyruvate to low-protein diets significantly reduced urinary nitrogen excretion from 13.2 g/d (18.0% crude protein, CP) to 10.3 g/d (15.0% CP) or 7.80 g/d (13.5% CP) and total nitrogen excretion from 22.5 g/d (18.0% CP) to 17.8 g/d (15.0% CP) or 14.2 g/d (13.5% CP) (P < 0.05), without obviously negative effects on the nitrogen retention (P > 0.05). Addition of calcium pyruvate to low-protein diets significantly decreased essential AA consumption rate in the liver (P < 0.05). This diet modification reduced the net portal fluxes of NH3, glycine, and alanine, as well as urea production rate in the liver (P < 0.05). The results indicated that pyruvate is an effective substitute for glutamate as a supplement in low-protein diets, reducing porcine nitrogen excretion and nitrogen consumption.
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Affiliation(s)
- Yunxia Li
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, P. R. China.,Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, P. R. China
| | - Zhiru Tang
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, P. R. China
| | - Tiejun Li
- Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha, P. R. China
| | - C Chen
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, P. R. China
| | - Feiruo Huang
- College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, P. R. China
| | - Jing Yang
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, P. R. China
| | - Qingqing Xu
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, P. R. China
| | - Jifu Zhen
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, P. R. China
| | - Zhaoliang Wu
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, P. R. China
| | - Mao Li
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, P. R. China
| | - Jiajing Sun
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, P. R. China
| | - Jinchao Chen
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, P. R. China
| | - Xiangxin Zhang
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, P. R. China
| | - Liuting Wu
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, P. R. China
| | - Rui An
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, P. R. China
| | - Shengjun Zhao
- School of Animal Science and Nutritional Engineering, Wuhan Polytechnic University, Wuhan, P. R. China
| | - Qingyan Jiang
- College of Animal Science and Technology, Huanan Agricultural University, Guangzhou, P. R. China
| | - Weiyun Zhu
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, P. R. China
| | - Yulong Yin
- Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha, P. R. China
| | - Zhihong Sun
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, P. R. China
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Hu L, Kristensen NB, Che L, Wu D, Theil PK. Net absorption and liver metabolism of amino acids and heat production of portal-drained viscera and liver in multiparous sows during transition and lactation. J Anim Sci Biotechnol 2020; 11:5. [PMID: 32082565 PMCID: PMC7014727 DOI: 10.1186/s40104-019-0417-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 12/15/2019] [Indexed: 02/06/2023] Open
Abstract
Background Determination of nutrient requirements in the late gestating and lactating sows is essential to optimize sow productivity. The objectives of the present study were to quantify amino acid (AA) fluxes and heat production across portal-drained viscera (PDV) and liver in multiparous sows during transition and lactation. Methods Eight second parity sows were fitted with indwelling catheters in the femoral artery and in the mesenteric, portal and hepatic veins. Eight hourly sets of blood samples were taken starting 0.5 h before feeding at - 10, - 3, + 3, and + 17 d in milk (DIM). Blood gases, plasma metabolites and apparent total tract digestibility (ATTD) of nutrients were measured. Results Feed intake, the ATTD of DM, energy, nitrogen, fat and crude fiber changed with DIM (P < 0.001). Except for Glu, O2, and urea, all net portal fluxes were positive, and all were affected by DIM (P < 0.05) and by sampling time (P < 0.01). Compared with pre partum levels, net portal uptake of AA was 3-63% lower at + 3 DIM but 40-100% higher at + 17 DIM. Net portal fluxes of AA peaked at 1.5 to 2.5 h after feeding except for Glu, and they were positively correlated with changes in sow feed intake across DIM. The net portal recovery was low for Met (49%), Thr (54%), and His (54%) and high for the remaining essential AA (63-69%) and none of them differed across DIM. Net hepatic uptake (i.e. hepatic oxidation) of Lys, Thr, Ile, Leu and Phe peaked at 0.5 to 2.5 h after feeding, whereas uptake of Trp, Val, and His was constant, while that of Met was close to zero. Conclusion The net portal recovery was substantially lower for Met, Thr, and His than the remaining essential AA. Hepatic AA oxidation peaks 0.5 to 2.5 h after feeding. The heat production in PDV and liver was approximately two-fold higher at peak lactation compared to other stages. The study suggests that lysine was the limiting AA in peak lactation but not in early lactation.
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Affiliation(s)
- Liang Hu
- 1Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Institute of Animal Nutrition, Sichuan Agricultural University, No. 211, Huimin Road, Wenjiang District, Chengdu, Sichuan 611130 People's Republic of China.,2Department of Animal Science, Faculty of Science and Technology, Aarhus University, DK-8830 Tjele, Denmark
| | - Niels Bastian Kristensen
- 2Department of Animal Science, Faculty of Science and Technology, Aarhus University, DK-8830 Tjele, Denmark.,Present address: SEGES Danish Pig Research Centre, DK-1609 Copenhagen, Denmark
| | - Lianqiang Che
- 1Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Institute of Animal Nutrition, Sichuan Agricultural University, No. 211, Huimin Road, Wenjiang District, Chengdu, Sichuan 611130 People's Republic of China
| | - De Wu
- 1Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Institute of Animal Nutrition, Sichuan Agricultural University, No. 211, Huimin Road, Wenjiang District, Chengdu, Sichuan 611130 People's Republic of China
| | - Peter Kappel Theil
- 2Department of Animal Science, Faculty of Science and Technology, Aarhus University, DK-8830 Tjele, Denmark
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Gao K, Pi Y, Mu C, Farzi A, Liu Z, Zhu W. Increasing carbohydrate availability in the hindgut promotes hypothalamic neurotransmitter synthesis: aromatic amino acids linking the microbiota–brain axis. J Neurochem 2019; 149:641-659. [DOI: 10.1111/jnc.14709] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 03/30/2019] [Accepted: 04/16/2019] [Indexed: 12/16/2022]
Affiliation(s)
- Kan Gao
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health College of Animal Science and Technology Nanjing Agricultural University Nanjing China
- National Center for International Research on Animal Gut Nutrition Nanjing Agricultural University Nanjing China
| | - Yu Pi
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health College of Animal Science and Technology Nanjing Agricultural University Nanjing China
- National Center for International Research on Animal Gut Nutrition Nanjing Agricultural University Nanjing China
| | - Chun‐Long Mu
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health College of Animal Science and Technology Nanjing Agricultural University Nanjing China
- National Center for International Research on Animal Gut Nutrition Nanjing Agricultural University Nanjing China
| | - Aitak Farzi
- Research Unit of Translational Neurogastroenterology Otto Loewi Research Center Pharmacology Section Medical University of Graz Graz Austria
| | - Zhuang Liu
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health College of Animal Science and Technology Nanjing Agricultural University Nanjing China
- National Center for International Research on Animal Gut Nutrition Nanjing Agricultural University Nanjing China
| | - Wei‐Yun Zhu
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health College of Animal Science and Technology Nanjing Agricultural University Nanjing China
- National Center for International Research on Animal Gut Nutrition Nanjing Agricultural University Nanjing China
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Wu L, Zhang X, Tang Z, Li Y, Li T, Xu Q, Zhen J, Huang F, Yang J, Chen C, Wu Z, Li M, Sun J, Chen J, An R, Zhao S, Jiang Q, Zhu W, Yin Y, Sun Z. Low-Protein Diets Decrease Porcine Nitrogen Excretion but with Restrictive Effects on Amino Acid Utilization. J Agric Food Chem 2018; 66:8262-8271. [PMID: 29984998 DOI: 10.1021/acs.jafc.8b03299] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Reducing dietary crude protein (CP) intake effectively decreases nitrogen excretion in growing-finishing pigs but at the expense of poor growth when dietary CP content is reduced by ≥3%. In this study, we investigated the main disadvantages of low-protein diets supplemented with lysine, methionine, threonine, and tryptophan in pigs. First, changes in the nitrogen balance in response to differences in dietary CP content (18%, 15%, and 13.5%) were investigated in barrows (40 kg). Then, barrows (40 kg) surgically fitted with catheters in the mesenteric vein, portal vein, hepatic vein, and carotid artery were used to investigate changes in amino acid (AA) metabolism in the portal-drained viscera and liver in response to differences in dietary CP content. The results showed that low-protein diets reduced fecal and urinary nitrogen excretion ( P < 0.05) meanwhile resulted in significant decreases in nitrogen retention ( P < 0.05). Moreover, a reduction in the dietary CP content from 18% to 13.5% resulted in decreases in the net portal fluxes of NH3, glycine, and alanine as well as in the urea production in the liver ( P < 0.05), whereas their values as a percentage of nitrogen intake did not decline ( P > 0.05). The net portal fluxes of nonessential AA (NEAA) were reduced in the low-protein diet groups ( P < 0.05), while essential AA consumption in the liver increased ( P < 0.05). Thus, low-protein diets result in reductions in both nitrogen excretion and retention, and NEAA deficiency may be a major disadvantage of low-protein diets.
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Affiliation(s)
- Liuting Wu
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology , Southwest University , Chongqing 400715 , P. R. China
| | - Xiangxin Zhang
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology , Southwest University , Chongqing 400715 , P. R. China
| | - Zhiru Tang
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology , Southwest University , Chongqing 400715 , P. R. China
| | - Yunxia Li
- Institute of Animal Nutrition , Sichuan Agricultural University , Chengdu 611130 , P. R. China
| | - Tiejun Li
- Institute of Subtropical Agriculture , The Chinese Academy of Sciences , Changsha 410125 , P. R. China
| | - Qingqing Xu
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology , Southwest University , Chongqing 400715 , P. R. China
| | - Jifu Zhen
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology , Southwest University , Chongqing 400715 , P. R. China
| | - Feiruo Huang
- College of Animal Science and Technology , Huazhong Agricultural University , Wuhan 430070 , P. R. China
| | - Jing Yang
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology , Southwest University , Chongqing 400715 , P. R. China
| | - Cheng Chen
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology , Southwest University , Chongqing 400715 , P. R. China
| | - Zhaoliang Wu
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology , Southwest University , Chongqing 400715 , P. R. China
| | - Mao Li
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology , Southwest University , Chongqing 400715 , P. R. China
| | - Jiajing Sun
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology , Southwest University , Chongqing 400715 , P. R. China
| | - Jinchao Chen
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology , Southwest University , Chongqing 400715 , P. R. China
| | - Rui An
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology , Southwest University , Chongqing 400715 , P. R. China
| | - Shengjun Zhao
- School of Animal Science and Nutritional Engineering , Wuhan Polytechnic University , Wuhan 430023 , P. R. China
| | - Qingyan Jiang
- College of Animal Science and Technology , Huanan Agricultural University , Guangzhou 510642 , P. R. China
| | - Weiyun Zhu
- College of Animal Science and Technology , Nanjing Agricultural University , Nanjing 210095 , P. R. China
| | - Yulong Yin
- Institute of Subtropical Agriculture , The Chinese Academy of Sciences , Changsha 410125 , P. R. China
| | - Zhihong Sun
- Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology , Southwest University , Chongqing 400715 , P. R. China
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Wang T, Yao W, He Q, Shao Y, Zheng R, Huang F. L-leucine stimulates glutamate dehydrogenase activity and glutamate synthesis by regulating mTORC1/SIRT4 pathway in pig liver. ACTA ACUST UNITED AC 2017; 4:329-337. [PMID: 30175263 PMCID: PMC6116330 DOI: 10.1016/j.aninu.2017.12.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 12/15/2017] [Indexed: 01/09/2023]
Abstract
The liver is the most essential organ for the metabolism of ammonia, in where most of ammonia is removed by urea and glutamine synthesis. Regulated by leucine, glutamate dehydrogenase (GDH) catalyzes the reversible inter-conversion of glutamate to ammonia. To determine the mechanism of leucine regulating GDH, pigs weighing 20 ± 1 kg were infused for 80 min with ammonium chloride or alanine in the presence or absence of leucine. Primary pig hepatocytes were incubated with or without leucine. In the in vivo experiments with either ammonium or alanine as the nitrogen source, addition of leucine significantly inhibited ureagenesis and promoted the production of glutamate and glutamine in the perfused pig liver (P < 0.05). Similarly, leucine stimulated GDH activity and inhibited sirtuin4 (SIRT4) gene expression (P < 0.01). Leucine could also activate mammalian target of rapamycin complex 1 (mTORC1) signaling (P < 0.05), as evidenced by the increased phosphorylation levels of ribosomal protein S6 kinase 1 (S6K1) and ribosomal protein S6 (S6). Interestingly, the leucine-induced mTORC1 pathway activation suitably correlated with increased GDH activity and decreased expression of SIRT4. Similar results were observed in primary cultured hepatocytes. Notably, leucine exerted no significant change in GDH activity in SIRT4-deficient hepatocytes (P > 0.05), while mTORC1 signaling was activated. Leucine exerted no significant changes in both GDH activity and SIRT4 gene expression in rapamycin treated hepatocytes (P > 0.05). In conclusion, L-leucine increases GDH activity and stimulates glutamate synthesis from different nitrogen sources by regulating mTORC1/SIRT4 pathway in the liver of pigs.
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Affiliation(s)
- Tongxin Wang
- Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Weilei Yao
- Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Qiongyu He
- Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yafei Shao
- Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Ruilong Zheng
- Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Feiruo Huang
- Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
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