scholarly journals Of Older Mice and Men: Branched-Chain Amino Acids and Body Composition

Nutrients ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1882 ◽  
Author(s):  
Rosilene V. Ribeiro ◽  
Samantha M. Solon-Biet ◽  
Tamara Pulpitel ◽  
Alistair M. Senior ◽  
Victoria C. Cogger ◽  
...  

Protein and branched-chain amino acid (BCAA) intake are associated with changes in circulating BCAAs and influence metabolic health in humans and rodents. However, the relationship between BCAAs and body composition in both species is unclear, with many studies questioning the translatability of preclinical findings to humans. Here, we assessed and directly compared the relationship between circulating BCAAs, body composition, and intake in older mice and men. Body weight and body fat were positively associated with circulating BCAA levels in both mouse and human, which remained significant after adjustments for age, physical activity, number of morbidities, smoking status, and source of income in the human cohort. Macronutrient intakes were similarly associated with circulating BCAA levels; however, the relationship between protein intake and BCAAs were more pronounced in the mice. These findings indicate that the relationship between circulating BCAAs, body composition, and intakes are comparable in both species, suggesting that the mouse is an effective model for examining the effects of BCAAs on body composition in older humans.

2018 ◽  
Vol 88 (1-2) ◽  
pp. 80-89 ◽  
Author(s):  
Zahra Shakibay Novin ◽  
Saeed Ghavamzadeh ◽  
Alireza Mehdizadeh

Abstract. Branched chain amino acids (BCAA), with vitamin B6 have been reported to improve fat metabolism and muscle synthesis. We hypothesized that supplementation with BCAA and vitamin B6 would result in more weight loss and improve body composition and blood markers related to cardiovascular diseases. Our aim was to determine whether the mentioned supplementation would affect weight loss, body composition, and cardiovascular risk factors during weight loss intervention. To this end, we performed a placebo-controlled randomized clinical trial in 42 overweight and obese women (BMI = 25–34.9 kg/m2). Taking a four-week moderate deficit calorie diet (–500 kcal/day), participants were randomized to receive BCAA (6 g/day) with vitamin B6 (40 mg/day) or placebo. Body composition variables measured with the use of bioelectrical impedance analysis, homeostatic model assessment, and plasma insulin, Low density lipoprotein, High density lipoprotein, Total Cholesterol, Triglyceride, and fasting blood sugar were measured. The result indicated that, weight loss was not significantly affected by BCAA and vitamin B6 supplementation (–2.43 ± 1.02 kg) or placebo (–1.64 ± 1.48 kg). However, significant time × treatment interactions in waist to hip ratio (P = 0.005), left leg lean (P = 0.004) and right leg lean (P = 0.023) were observed. Overall, supplementation with BCAA and vitamin B6 could preserve legs lean and also attenuated waist to hip ratio.


2019 ◽  
Vol 20 (7) ◽  
pp. 644-651 ◽  
Author(s):  
Changsong Gu ◽  
Xiangbing Mao ◽  
Daiwen Chen ◽  
Bing Yu ◽  
Qing Yang

Branched chain amino acids are the essential nutrients for humans and many animals. As functional amino acids, they play important roles in physiological functions, including immune functions. Isoleucine, as one of the branched chain amino acids, is also critical in physiological functions of the whole body, such as growth, immunity, protein metabolism, fatty acid metabolism and glucose transportation. Isoleucine can improve the immune system, including immune organs, cells and reactive substances. Recent studies have also shown that isoleucine may induce the expression of host defense peptides (i.e., β-defensins) that can regulate host innate and adaptive immunity. In addition, isoleucine administration can restore the effect of some pathogens on the health of humans and animals via increasing the expression of β-defensins. Therefore, the present review will emphatically discuss the effect of isoleucine on immunity while summarizing the relationship between branched chain amino acids and immune functions.


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.


1978 ◽  
Vol 234 (5) ◽  
pp. E494 ◽  
Author(s):  
H S Paul ◽  
S A Adibi

The effect of L-carnitine (0.5-2.0 mM) on the rates of alpha-decarboxylation of 1-14C-labeled branched-chain amino acids by gastrocnemius muscle and liver homogenates of fed rats was investigated. Carnitine increased the rate of alpha-decarboxylation of leucine (125%) and valine (28%) by muscle, but it was without effect on the oxidation of these amino acids by liver. Carnitine increased the rate of alpha-decarboxylation of alpha-ketoisocaproate by both tissues. This effect was more pronounced in muscle (130% increase) than in liver (41% increase). The activity of carnitine acyltransferase, with isovaleryl-CoA as a substrate, was 18 times higher in muscle mitochondria than in liver mitochondria. Both starvation and diabetes increased the rate of alpha-decarboxylation of leucine by muscle without having a remarkable effect on the concentration of carnitine or the activity of carnitine acyltransferase. We conclude that: a) carnitine stimulates decarboxylation of branched-chain amino acids by increasing the conversion of their ketoanalogues into carnitine esters, b) a greater carnitine acyltransferase activity in muscle than in liver may be responsible for the greater carnitine effect in muscle, c) carnitine does not appear responsible for the enhancement of leucine oxidation by muscle of starved and diabetic rats.


1978 ◽  
Vol 235 (1) ◽  
pp. E47
Author(s):  
W E Mitch ◽  
W Chan

Isolated rat kidney perfused without substrate released serine, glycine, and taurine, and substantially smaller amounts of other amino acids. When branched-chain keto acids were added, the corresponding amino acids were released at rates amounting to 15-25% of keto acid disappearance. Perfusion with 2 mM alpha-keto-isovalerate or alpha-keto-beta-methylvalerate caused an increased glucose release amounting to 18-23% of keto acid disappearance. The activity of branched-chain amino acid transferase (BATase) was significantly stimulated by perfusion with the analogue of leucine, but not by perfusion with alpha-ketoglutarate, the analogues of valine or isoleucine, or with leucine itself. These findings document that the kidney converts branched-chain keto acids in part to the corresponding amino acids and suggest that the keto analogue of leucine may be involved in the control of renal BATase activity, thereby indirectly regulating the metabolism of branched-chain amino acids.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Karin Shimada ◽  
Isao Matsui ◽  
Kazunori Inoue ◽  
Ayumi Matsumoto ◽  
Seiichi Yasuda ◽  
...  

Abstract Dietary phosphate intake is closely correlated with protein intake. However, the effects of the latter on phosphate-induced organ injuries remain uncertain. Herein, we investigated the effects of low (10.8%), moderate (23.0%), and high (35.2%) dietary casein and egg albumin administration on phosphate-induced organ injuries in rats. The moderate and high casein levels suppressed renal tubulointerstitial fibrosis and maintained mitochondrial integrity in the kidney. The serum creatinine levels were suppressed only in the high casein group. Phosphate-induced muscle weakness was also ameliorated by high dietary casein. The urinary and fecal phosphate levels in the early experiment stage showed that dietary casein did not affect phosphate absorption from the intestine. High dietary egg albumin showed similar kidney protective effects, while the egg albumin effects on muscle weakness were only marginally significant. As the plasma branched-chain amino acid levels were elevated in casein- and egg albumin-fed rats, we analyzed their effects. Dietary supplementation of 10% branched-chain amino acids suppressed phosphate-induced kidney injury and muscle weakness. Although dietary protein restriction is recommended in cases of chronic kidney disease, our findings indicate that the dietary casein, egg albumin, and branched-chain amino acid effects might be reconsidered in the era of a phosphate-enriched diet.


2010 ◽  
Vol 76 (5) ◽  
pp. 1507-1515 ◽  
Author(s):  
Motoyuki Shimizu ◽  
Tatsuya Fujii ◽  
Shunsuke Masuo ◽  
Naoki Takaya

ABSTRACT Although branched-chain amino acids are synthesized as building blocks of proteins, we found that the fungus Aspergillus nidulans excretes them into the culture medium under hypoxia. The transcription of predicted genes for synthesizing branched-chain amino acids was upregulated by hypoxia. A knockout strain of the gene encoding the large subunit of acetohydroxy acid synthase (AHAS), which catalyzes the initial reaction of the synthesis, required branched-chain amino acids for growth and excreted very little of them. Pyruvate, a substrate for AHAS, increased the amount of hypoxic excretion in the wild-type strain. These results indicated that the fungus responds to hypoxia by synthesizing branched-chain amino acids via a de novo mechanism. We also found that the small subunit of AHAS regulated hypoxic branched-chain amino acid production as well as cellular AHAS activity. The AHAS knockout resulted in higher ratios of NADH/NAD+ and NADPH/NADP+ under hypoxia, indicating that the branched-chain amino acid synthesis contributed to NAD+ and NADP+ regeneration. The production of branched-chain amino acids and the hypoxic induction of involved genes were partly repressed in the presence of glucose, where cells produced ethanol and lactate and increased levels of lactate dehydrogenase activity. These indicated that hypoxic branched-chain amino acid synthesis is a unique alternative mechanism that functions in the absence of glucose-to-ethanol/lactate fermentation and oxygen respiration.


1983 ◽  
Vol 210 (2) ◽  
pp. 451-455 ◽  
Author(s):  
N G Anderson ◽  
P J Hanson

1. A method is described for measuring arteriovenous differences across the rat stomach in vivo. 2. Notable results were the uptake of branched-chain amino acids, the uptake of arginine, which was approximately balanced by an output of ornithine, and the output of alanine. 3. The fractional extraction of glutamine from the blood by the stomach wall of pentagastrin-stimulated rats was 4.7%. 4. The arteriovenous differences for ammonia depended upon the blood ammonia concentration. 5. Arteriovenous differences were not affected by the stimulation of acid secretion with pentagastrin. 6. It is concluded that the high activity of branched-chain-amino-acid aminotransferase (EC 2.6.1.42) in the gastric mucosa is associated with metabolism of these amino acids, but that the stomach wall is a less avid user of glutamine than is the small intestine.


1994 ◽  
Vol 86 (3) ◽  
pp. 339-345 ◽  
Author(s):  
M. A. McNurlan ◽  
S. D. Heys ◽  
K. G. M. Park ◽  
J. Broom ◽  
D. S. Brown ◽  
...  

1 Rates of protein synthesis have been measured from the incorporation of 57 mg of l-[1-13C]leucine/kg for 90 min into muscle tissue and colorectal tumours removed at surgery from cancer patients. 2. For the 20 h preceding surgery and during the measurement of protein synthesis, the patients received intravenous saline, conventional intravenous nutrition (0.2 g of N and 103 non-protein kJ/kg body weight) or intravenous nutrition enriched with the branched-chain amino acids leucine, isoleucine and valine (0.2 g of N with 30% from branched-chain amino acids and 103 non-protein kJ/kg body weight). 3. Conventional intravenous nutrition resulted in a significant stimulation of the rate of protein synthesis in both muscle tissue (2.64 ± 0.75%/day versus 1.78 ± 0.51%/day in saline control, means ± SD) and tumour tissue (43.9 ± 10.3%/day versus 22.6 ± 5.6%/day in saline control). 4. Pre-operative nutrition enriched with branched-chain amino acids was less effective than conventional intravenous nutrition in stimulating protein synthesis in both muscle and tumour. The rates of protein synthesis were 2.12 ± 0.41%/day in muscle and 33.7 ± 5.3%/day in the tumours. 5. The expression of proliferating cell nuclear antigen in sections of the tumours showed changes with intravenous feeding of the two different amino acid mixtures that were similar to the changes in protein synthesis, and these two variables were significantly correlated. This is evidence that feeding with conventional mixtures and mixtures enriched with branched-chain amino acids stimulates tumour growth. 6. In this study the mixture enriched with branched-chain amino acids provided no clear advantage for cancer patients, since a smaller response to branched-chain amino acids was observed in both tumours and host muscle tissue.


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