scholarly journals Effects on nitrogen balance and metabolism of branched-chain amino acids by growing pigs of supplementing isoleucine and valine to diets with adequate or excess concentrations of dietary leucine

2020 ◽  
Vol 98 (11) ◽  
Author(s):  
Woong B Kwon ◽  
Jose A Soto ◽  
Hans H Stein

Abstract Diets based on high levels of corn protein have elevated concentrations of Leu, which may negatively affect N retention in pigs. An experiment was, therefore, conducted to test the hypothesis that Ile and Val supplementation may overcome the detrimental effects of excess dietary Leu on N balance and metabolism of branched-chain amino acids (BCAA) in growing pigs. A total of 144 barrows (initial body weight: 28.5 kg) were housed in metabolism crates and randomly assigned to 1 of 18 dietary treatments. The basal diet contained 0.98% standardized ileal digestible (SID) Lys and had SID Leu, Val, and Ile ratios to SID Lys of 100%, 60%, and 43%, respectively. Crystalline l-Leu (0% or 2.0%), l-Ile (0%, 0.1%, or 0.2%), and l-Val (0%, 0.1%, or 0.2%) were added to the basal diet resulting in a total of 18 dietary treatments that were arranged in a 2 × 3 × 3 factorial. Urine and fecal samples were collected for 5 d after 7 d of adaptation. Blood, skeletal muscle, and liver samples were collected at the conclusion of the experiment. There were no three-way interactions among the main effects. Excess Leu in diets reduced (P < 0.05) N retention and biological value of protein and increased (P < 0.001) plasma urea N (PUN), but PUN was reduced (P < 0.05) as dietary Val increased. Concentrations of Leu in the liver were greater (P < 0.001) in pigs fed excess Leu diets than in pigs fed adequate Leu diets, but concentrations of BCAA in muscle were greater (P < 0.05) in pigs fed low-Leu diets. Increasing dietary Ile increased (P < 0.001) plasma-free Ile and plasma concentration of the Ile metabolite, α-keto-β-methylvalerate, but the increase was greater in diets without excess Leu than in diets with excess Leu (interaction, P < 0.001). Plasma concentrations of Val and the Val metabolite α-keto isovalerate increased (P < 0.001) with increasing dietary Val in diets with adequate Leu, but not in diets with excess Leu (interaction, P < 0.001). Increasing dietary Leu increased (P < 0.001) plasma-free Leu and plasma concentration of the Leu metabolite, α-keto isocaproate (KIC). In contrast, increased dietary Val reduced (P < 0.05) the plasma concentration of KIC. In conclusion, excess dietary Leu reduced N retention and increased PUN in growing pigs, but Val supplementation to excess Leu diets may increase the efficiency of amino acid utilization for protein synthesis as indicated by reduced PUN.

2000 ◽  
Vol 83 (1) ◽  
pp. 49-58 ◽  
Author(s):  
Stefan Langer ◽  
Peter W. D. Scislowski ◽  
David S. Brown ◽  
Peter Dewey ◽  
Malcolm F. Fuller

The present experiment was designed to elucidate the mechanism of the methionine-sparing effect of excess branched-chain amino acids (BCAA) reported in the previous paper (Langer & Fuller, 2000). Twelve growing gilts (30–35 kg) were prepared with arterial catheters. After recovery, they received for 7 d a semipurified diet with a balanced amino acid pattern. On the 7th day blood samples were taken before (16 h postabsorptive) and after the morning meal (4 h postprandial). The animals were then divided into three groups and received for a further 7 d a methionine-limiting diet (80 % of requirement) (1) without any amino acid excess; (2) with excess leucine (50 % over requirement); or (3) with excesses of all three BCAA (leucine, isoleucine, valine, each 50 % over the requirement). On the 7th day blood samples were taken as in the first period, after which the animals were killed and liver and muscle samples taken. Plasma amino acid and branched-chain keto acid (BCKA) concentrations in the blood and branched-chain keto-acid dehydrogenase (BCKDH; EC 1.2.4.4) activity in liver and muscle homogenates were determined. Compared with those on the balanced diet, pigs fed on methionine-limiting diets had significantly lower (P < 0·05) plasma methionine concentrations in the postprandial but not in the postabsorptive state. There was no effect of either leucine or a mixture of all three BCAA fed in excess on plasma methionine concentrations. Excess dietary leucine reduced (P < 0·05) the plasma concentrations of isoleucine and valine in both the postprandial and postabsorptive states. Plasma concentrations of the BCKA reflected the changes in the corresponding amino acids. Basal BCKDH activity in the liver and total BCKDH activity in the biceps femoris muscle were significantly (P < 0·05) increased by excesses of leucine or all BCAA.


2018 ◽  
Vol 120 (4) ◽  
pp. 445-453 ◽  
Author(s):  
Inger Ottestad ◽  
Stine M. Ulven ◽  
Linn K. L. Øyri ◽  
Kristin S. Sandvei ◽  
Gyrd O. Gjevestad ◽  
...  

AbstractBranched-chain amino acids (BCAA) are essential amino acids that are necessary for muscle mass maintenance. Little is known about the plasma concentrations of BCAA and the protein intake in relation to sarcopenia. We aimed to compare the non-fasting plasma concentrations of the BCAA and the dietary protein intake between sarcopenic and non-sarcopenic older adults. Norwegian older home-dwelling adults (≥70 years) were invited to a cross-sectional study with no other exclusion criteria than age. Sarcopenic subjects were defined by the diagnostic criteria by the European Working Group on Sarcopenia in Older People. Non-fasting plasma concentrations of eight amino acids were quantified using NMR spectroscopy. Protein intake was assessed using 2×24-h dietary recalls. In this study, ninety out of 417 subjects (22 %) were sarcopenic, and more women (32 %) than men (11 %) were sarcopenic (P<0·0001). Sex-adjusted non-fasting plasma concentrations of leucine and isoleucine, and the absolute intake of protein (g/d), were significantly lower among the sarcopenic subjects, when compared with non-sarcopenic subjects (P=0·003, P=0·026 and P=0·003, respectively). A similar protein intake was observed in the two groups when adjusted for body weight (BW) and sex (1·1 g protein/kg BW per d; P=0·50). We show that sarcopenia is associated with reduced non-fasting plasma concentration of the BCAA leucine and isoleucine, and lower absolute intake of protein. More studies are needed to clarify the clinical relevance of these findings, related to maintenance of muscle mass and prevention of sarcopenia.


2000 ◽  
Vol 84 (2) ◽  
pp. 157-163 ◽  
Author(s):  
T. Obitsu ◽  
D. Bremner ◽  
E. Milne ◽  
G. E. Lobley

The effect of abomasal infusion of glucose (120 kJ/d per kg body weight (BW)0·75, 758 mmol/d) on urea production, plasma alanine-N flux rate and the conversion of alanine-N to urea was studied in sheep offered a low-N diet at limited energy intake (500 kJ/d per kg BW0·75), based on hay and grass pellets. Glucose provision reduced urinary N (P= 0·040) and urea (P= 0·009) elimination but this was offset by poorer N digestibility. Urea-N production was significantly reduced (822v. 619 mmol/d,P= 0·024) by glucose while plasma alanine-N flux rate was elevated (295v. 342 mmol/d,P= 0·011). The quantity of urea-N derived from alanine tended to be decreased by glucose (127v. 95 mmol/d) but the fraction of urea production from alanine was unaltered (15 %). Plasma urea and alanine concentrations (plus those of the branched chain amino acids) decreased in response to exogenous glucose, an effect probably related to enhanced anabolic usage of amino acids and lowered urea production.


2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Ryoko Katagiri ◽  
Atsushi Goto ◽  
Sanjeev Budhathoki ◽  
Taiki Yamaji ◽  
Hiroshi Yamamoto ◽  
...  

1991 ◽  
Vol 274 (2) ◽  
pp. 395-400 ◽  
Author(s):  
K Melde ◽  
S Jackson ◽  
K Bartlett ◽  
H S A Sherratt ◽  
S Ghisla

We describe the effects of methylenecyclopropylglycine in fasted rats. A 75% decrease in the blood glucose concentration and an increase of lactate and pyruvate were observed 6 h after administration of 100 mg of this amino acid/kg. By contrast with the effects reported for hypoglycin [Williamson & Wilson (1965) Biochem. J. 94, 19c-21c], the plasma concentrations of ketone bodies decreased after administration of methylenecyclopropylglycine and the concentrations of branched-chain amino acids in the plasma were increased 6-fold. The oxidation of decanoylcarnitine or of palmitate was nearly completely inhibited in rat liver mitochondria from methylenecyclopropylglycine-poisoned rats. The activities of acetoacetyl-CoA and of 3-oxoacyl-CoA thiolase were decreased to 25% and less than 10% of the controls. There was a pronounced aciduria, due to the excretion of dicarboxylic acids and of oxidation products of branched-chain amino acids. The accumulation of the toxic metabolite methylenecyclopropylformyl-CoA in the mitochondrial matrix was detected after administration of methylenecyclopropylglycine. Similarly we confirmed experimentally that methylenecyclopropylacetyl-CoA accumulates in mitochondria incubated with methylenecyclopropylpyruvate.


2004 ◽  
Vol 82 (7) ◽  
pp. 506-514 ◽  
Author(s):  
Enoka P Wijekoon ◽  
Craig Skinner ◽  
Margaret E Brosnan ◽  
John T Brosnan

We investigated amino acid metabolism in the Zucker diabetic fatty (ZDF Gmi fa/fa) rat during the prediabetic insulin-resistant stage and the frank type 2 diabetic stage. Amino acids were measured in plasma, liver, and skeletal muscle, and the ratios of plasma/liver and plasma/skeletal muscle were calculated. At the insulin-resistant stage, the plasma concentrations of the gluconeogenic amino acids aspartate, serine, glutamine, glycine, and histidine were decreased in the ZDF Gmi fa/fa rats, whereas taurine, α-aminoadipic acid, methionine, phenylalanine, tryptophan, and the 3 branched-chain amino acids were significantly increased. At the diabetic stage, a larger number of gluconeogenic amino acids had decreased plasma concentrations. The 3 branched-chain amino acids had elevated plasma concentrations. In the liver and the skeletal muscles, concentrations of many of the gluconeogenic amino acids were lower at both stages, whereas the levels of 1 or all of the branched-chain amino acids were elevated. These changes in amino acid concentrations are similar to changes seen in type 1 diabetes. It is evident that insulin resistance alone is capable of bringing about many of the changes in amino acid metabolism observed in type 2 diabetes.Key words: plasma amino acids, liver amino acids, muscle amino acids, gluconeogenesis.


2018 ◽  
Vol 64 (8) ◽  
pp. 1203-1210 ◽  
Author(s):  
Deirdre K Tobias ◽  
Clary Clish ◽  
Samia Mora ◽  
Jun Li ◽  
Liming Liang ◽  
...  

Abstract BACKGROUND Circulating branched-chain amino acids (BCAAs; isoleucine, leucine, valine) are consistently associated with increased type 2 diabetes (T2D) risk, but the relationship with dietary intake of BCAAs is less clear. METHODS The longitudinal Nurses' Health Study II cohort conducted a blood collection from 1996 to 1999. We profiled plasma metabolites among 172 incident T2D cases and 175 age-matched controls from women reporting a history of gestational diabetes before blood draw. We estimated dietary energy-adjusted BCAAs from food frequency questionnaires. We used conditional logistic regression models to estimate odds ratios (OR) and 95% CI of T2D risk across quartiles (Q1–Q4) of BCAAs, adjusting for age, body mass index (BMI), physical activity, family history, and other established risk factors. We also assessed joint exposure to below/above medians of diet and plasma concentrations, with lower diet/lower plasma as reference. RESULTS Dietary and plasma BCAA concentrations were positively associated with incident T2D (diet Q4 vs Q1 OR = 4.6, CI = 1.6, 13.4; plasma Q4 vs Q1 OR = 4.4, CI = 1.4, 13.4). Modeling the joint association indicated that higher diet BCAAs were associated with T2D when plasma concentrations were also higher (OR = 6.0, CI = 2.1, 17.2) but not when concentrations were lower (OR = 1.6, CI = 0.61, 4.1). Conversely, higher plasma BCAAs were associated with increased T2D for either lower or higher diet. CONCLUSIONS Independent of BMI and other risk factors, higher diet and plasma BCAA concentrations were associated with an increased incident T2D risk among high-risk women with a history of gestational diabetes, supporting impaired BCAA metabolism as conferring T2D risk.


Author(s):  
William O Jonsson ◽  
Jonathan Ponette ◽  
Oscar Horwath ◽  
Tomas Rydenstam ◽  
Karin Söderlund ◽  
...  

Administration of branched-chain amino acids (BCAA) has been suggested to enhance mitochondrial biogenesis, including levels of PGC-1α, which may, in turn, alter kynurenine metabolism. Ten healthy subjects performed 60 min of dynamic one-leg exercise at ~70% of Wmax on two occasions. They were in random order supplied either a mixture of BCAA or flavored water (placebo) during the experiment. Blood samples were collected during exercise and recovery, and muscle biopsies were taken from both legs before, after and 90 and 180 min following exercise. Ingestion of BCAA doubled their concentration in both plasma and muscle while causing a 30-40% reduction (P<0.05 vs. placebo) in levels of aromatic amino acids in both resting and exercising muscle during 3-h recovery. The muscle concentration of kynurenine decreased by 25% (P<0.05) during recovery, similar in both resting and exercising leg and with both supplements, although plasma concentration of kynurenine during recovery was 10% lower (P<0.05) when BCAA were ingested. Ingestion of BCAA reduced the plasma concentration of kynurenic acid by 60% (P<0.01) during exercise and recovery, while the level remained unchanged with placebo. Exercise induced a 3-4-fold increase (P<0.05) in muscle content of PGC-1a1 mRNA after 90 min of recovery under both conditions, whereas levels of KAT4 mRNA and protein were unaffected by exercise or supplement. In conclusion, the reduction of plasma levels of kynurenine and kynurenic acid caused by BCAA were not associated with any changes in the level of muscle kynurenine, suggesting that kynurenine metabolism was altered in tissues other than muscle.


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