Protein synthesis is stimulated by resistance exercise and intake of amino acids, in particular leucine. Moreover, activation of mammalian target of rapamycin complex 1 (mTORC1) signaling by leucine is potentiated by the presence of other essential amino acids (EAA). However, the contribution of the branched-chain amino acids (BCAA) to this effect is yet unknown. Here we compare the stimulatory role of leucine, BCAA, and EAA ingestion on anabolic signaling following exercise. Accordingly, eight trained volunteers completed four sessions of resistance exercise during which they ingested either placebo, leucine, BCAA, or EAA (including the BCAA) in random order. Muscle biopsies were taken at rest, immediately after exercise, and following 90 and 180 min of recovery. Following 90 min of recovery the activity of S6 kinase 1 (S6K1) was greater than at rest in all four trials (Placebo
5.
Human Muscle Protein Synthetic Responses during Weight-Bearing and Non-Weight-Bearing Exercise: A Comparative Study of Exercise Modes and Recovery Nutrition.
Pasiakos, SM, McClung, HL, Margolis, LM, Murphy, NE, Lin, GG, Hydren, JR, Young, AJ
PloS one. 2015;(10):e0140863
Abstract
Effects of conventional endurance (CE) exercise and essential amino acid (EAA) supplementation on protein turnover are well described. Protein turnover responses to weighted endurance exercise (i.e., load carriage, LC) and EAA may differ from CE, because the mechanical forces and contractile properties of LC and CE likely differ. This study examined muscle protein synthesis (MPS) and whole-body protein turnover in response to LC and CE, with and without EAA supplementation, using stable isotope amino acid tracer infusions. Forty adults (mean ± SD, 22 ± 4 y, 80 ± 10 kg, VO 2peak 4.0 ± 0.5 L ∙ min(-1)) were randomly assigned to perform 90 min, absolute intensity-matched (2.2 ± 0.1 VO2 L ∙ m(-1)) LC (performed on a treadmill wearing a vest equal to 30% of individual body mass, mean ± SD load carried 24 ± 3 kg) or CE (cycle ergometry performed at the same absolute VO2 as LC) exercise, during which EAA (10 g EAA, 3.6 g leucine) or control (CON, non-nutritive) drinks were consumed. Mixed-muscle and myofibrillar MPS were higher during exercise for LC than CE (mode main effect, P < 0.05), independent of dietary treatment. EAA enhanced mixed-muscle and sarcoplasmic MPS during exercise, regardless of mode (drink main effect, P < 0.05). Mixed-muscle and sarcoplasmic MPS were higher in recovery for LC than CE (mode main effect, P < 0.05). No other differences or interactions (mode x drink) were observed. However, EAA attenuated whole-body protein breakdown, increased amino acid oxidation, and enhanced net protein balance in recovery compared to CON, regardless of exercise mode (P < 0.05). These data show that, although whole-body protein turnover responses to absolute VO2-matched LC and CE are the same, LC elicited a greater muscle protein synthetic response than CE.
6.
Dietary essential amino acids are highly anabolic in pediatric patients with cystic fibrosis.
Engelen, MP, Com, G, Wolfe, RR, Deutz, NE
Journal of cystic fibrosis : official journal of the European Cystic Fibrosis Society. 2013;(5):445-53
Abstract
BACKGROUND Current nutritional approaches have been partially successful in Cystic Fibrosis (CF). Essential amino acids mixtures with high Leucine levels (EAA) have anabolic properties in catabolic conditions, however data in CF are lacking. METHODS On two days according a randomized crossover design, 15 pediatric CF patients ingested 6.7 g EAA versus mixture of total amino acids as present in whey. Whole body protein and Arginine metabolism (as EAA lack Arginine) were assessed by stable isotope methodology. RESULTS Protein synthesis (P<0.05) but not protein breakdown was higher after EAA and 70% higher values for net anabolism (P<0.001)were found both in patients with and without nutritional failure. Arginine turnover was lower (P<0.001) and de novo Arginine synthesis tended lower (P=0.09) after EAA. Nitric oxide synthesis was not different. CONCLUSIONS CF patients are highly responsive to EAA intake independent of their nutritional status. Addition of Arginine to the EAA mixture may be warranted in CF.
7.
Effects of exercise and amino acid supplementation on body composition and physical function in community-dwelling elderly Japanese sarcopenic women: a randomized controlled trial.
Kim, HK, Suzuki, T, Saito, K, Yoshida, H, Kobayashi, H, Kato, H, Katayama, M
Journal of the American Geriatrics Society. 2012;(1):16-23
Abstract
OBJECTIVES To evaluate the effectiveness of exercise and amino acid supplementation in enhancing muscle mass and strength in community-dwelling elderly sarcopenic women. DESIGN Randomized controlled trial. SETTING Urban community in Tokyo, Japan. PARTICIPANTS One hundred fifty-five women aged 75 and older were defined as sarcopenic and randomly assigned to one of four groups: exercise and amino acid supplementation (exercise + AAS; n = 38), exercise (n = 39), amino acid supplementation (AAS; n = 39), or health education (HE; n = 39). INTERVENTION The exercise group attended a 60-minute comprehensive training program twice a week, and the AAS group ingested 3 g of a leucine-rich essential amino acid mixture twice a day for 3 months. MEASUREMENTS Body composition was determined using bioelectrical impedance analysis. Data from interviews and functional fitness parameters such as muscle strength and walking ability were collected at baseline and after the 3-month intervention. RESULTS A significant group × time interaction was seen in leg muscle mass (P = .007), usual walking speed (P = .007), and knee extension strength (P = .017). The within-group analysis showed that walking speed significantly increased in all three intervention groups, leg muscle mass in the exercise + AAS and exercise groups, and knee extension strength only in the exercise + AAS group (9.3% increase, P = .01). The odds ratio for leg muscle mass and knee extension strength improvement was more than four times as great in the exercise + AAS group (odds ratio = 4.89, 95% confidence interval = 1.89-11.27) as in the HE group. CONCLUSION The data suggest that exercise and AAS together may be effective in enhancing not only muscle strength, but also combined variables of muscle mass and walking speed and of muscle mass and strength in sarcopenic women.
8.
Essential amino acid supplementation in patients with severe COPD: a step towards home rehabilitation.
Dal Negro, RW, Testa, A, Aquilani, R, Tognella, S, Pasini, E, Barbieri, A, Boschi, F
Monaldi archives for chest disease = Archivio Monaldi per le malattie del torace. 2012;(2):67-75
Abstract
BACKGROUND Pulmonary Rehabilitation ("Rehabilitation") can improve both lung function and quality of life in patients suffering from chronic obstructive pulmonary disease (COPD) even if only a very small proportion of patients have access to Rehabilitation. Supplementation of Essential Amino Acids (EAAs) might allow COPD patients to achieve some typical Rehabilitation outcomes such as a better physical performance and an improved health status. METHODS 88 COPD out-patients (GOLD class 3-4) with a body mass index (BMI) < 23 Kg/m2 were randomised to receive EAAs (n = 44) or placebo (n = 44) for twelve weeks. Primary outcome measures were changes in both physical activities in daily life (measured by Sense Wear Armband in terms of mean steps walked in one week) and in quality of life (measured by the St George's Respiratory Questionnaire, SGRQ). RESULTS After 12 weeks, the physical performance was significantly increased vs baseline only in patients who received EAAs (1140.33 +/- 524.69 and 638.68 +/- 662.1 steps/day, respectively; p = 0.02), being also the comparison vs the placebo group highly significant (p = 0.003). Similarly, the SGRQ score improved significantly only in EAA patients (69.35 +/- 9.51 vs baseline 72.04 +/- 8.62; p < 0.01), and changes were significantly different from those measured in the placebo group (p < 0.001). Furthermore, when compared to those who received placebo, EAAs patients significantly increased their fat-free mass (p = 0.04), muscle strength (p < 0.01), saturation of oxygen (p = 0.05), serum albumin (p < 0.001), and also ameliorated their original cognitive dysfunction (p = 0.02). CONCLUSIONS Oral supplementation with EAAs contribute to improve the daily-life performance in domiciliary severe COPD patients who can not enter any Rehabilitation programme, together with their quality of life; nutritional and cognitive status, and muscle strength.
9.
Adequate energy-protein intake is not enough to improve nutritional and metabolic status in muscle-depleted patients with chronic heart failure.
Aquilani, R, Opasich, C, Gualco, A, Verri, M, Testa, A, Pasini, E, Viglio, S, Iadarola, P, Pastoris, O, Dossena, M, et al
European journal of heart failure. 2008;(11):1127-35
Abstract
BACKGROUND An adequate energy-protein intake (EPI) when combined with amino acid supplementation may have a positive impact on nutritional and metabolic status in patients with chronic heart failure (CHF). METHODS AND RESULTS Thirty eight stable CHF patients (27 males, 73.5+/-4 years; BMI 22.5+/-1.4 kg/m2), with severe depletion of muscle mass and were randomised to oral supplements of essential amino acids 8 g/day (EAA group; n=21) or no supplements (controls; n=17). All patients had adequate EPI (energy> or =30 kcal/kg; proteins >1.1 g/kg). At baseline and 2-months after randomisation, the patients underwent metabolic (plasma lactate, pyruvate concentration; serum insulin level; estimate of insulin resistance by HOMA index), nutritional (measure of nitrogen balance), and functional (exercise test, walking test) evaluations. Body weight increased by >1 kg in 80% of supplemented patients (mean 2.96 kg) and in 30% of controls (mean 2.3 kg) (interaction <0.05). Changes in arm muscle area, nitrogen balance, and HOMA index were similar between the two treatment groups. Plasma lactate and pyruvate levels increased in controls (p<0.01 for both) but decreased in the supplemented group (p<0.01 and 0.02 respectively). EAA supplemented patients but not controls improved both exercise output and peak oxygen consumption and walking test. CONCLUSIONS Adequate EPI when combined with essential amino acid supplementation may improve nutritional and metabolic status in most muscle-depleted CHF patients.
10.
Oral amino acid administration decreases oxidative stress and improves brachial reactivity in elderly individuals.
Manzella, D, Grella, R, Esposito, K, Cacciapuoti, F, Arciello, A, Giugliano, D, Paolisso, G
American journal of hypertension. 2005;(6):858-63
Abstract
BACKGROUND Atherosclerosis is a major cause of death in elderly individuals. Endothelial dysfunction is recognized as a key early event in atherogenesis. In the present study, we evaluated the possible beneficial effect of amino acid administration on endothelial regulation in elderly subjects. METHODS A total of 25 healthy elderly subjects were administered essential amino acids (EAA) for 4 months. Before and after EAA administration, each subject underwent brachial reactivity investigation with and without an intra-arterial infusion of 4 micromol/min of N(G)-monomethyl-l-arginine (L-NMMA), an inhibitor of nitric oxide (NO) synthase. RESULTS At baseline, age correlated with free plasma insulin growth factor-1 IGF-1 (r = -0.48; P < .01), plasma Trolox equivalent antioxidant capacity (TEAC) (r = -0.40; P < .04), and thiobarbituric acid-reactive substances (TBARS) (r = 0.42, P < .04), and homeostasis model assessment (HOMA) index (r = 0.45, P < .03), as well as with changes in diameter (r = -0.49, P < .01) and flow (r = -0.43, P < .03). Administration of EAA was associated with a significant increase in plasma TEAC (P < .001) and decline in plasma TBARS (P < .001) and with improvement in changes in diameter (7.15 +/-1.10 v 8.98 +/-1.80, P < .001) and flow (5.6 +/-1.2 v 6.4 +/- 1.2, P < .03). These latter two associations were independent of changes in HOMA index (P < .04 for both correlations). The beneficial effects of EAA administration on brachial reactivity were partly attenuated by L-NMMA. CONCLUSIONS Administration of EAA may improve brachial reactivity in elderly persons and may also protect against the development of atherosclerosis via the rise in plasma-free IGF-1 levels.