Differential effects of leucine and leucine-enriched whey protein on skeletal muscle protein synthesis in aged mice

Dijk, Francina J.; Dijk, M. van; Walrand, Stéphane; Loon, Luc J. C. van; Norren, Klaske van; Luiking, Yvette C.

doi:10.1016/j.clnesp.2017.12.013

Cited by 25 publications

(26 citation statements)

References 45 publications

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“…Leucine supplementation had no significant effect on the 3‐MH concentration in skeletal muscle，which is a special maker of protein degradation, but increased the protein concentration of skeletal muscle and concentrations of EAAs in serum. These results indicate that protein degradation in the skeletal muscle remained unchanged in response to leucine supplementation, resulting in a similar amount of EAAs releasing into the metabolic pool; however, the increase of serum EAAs by leucine may have been resulted from a reduction of the loss of EAAs from the metabolic pool, probably by inhibited oxidation of EAAs (Holecek et al, ) and then increased the concentrations of EAAs in LEU (Dijk et al, ). In addition, previous researches also showed that supplementation of leucine can increase AA utilization (Boutry et al, ; Rudar et al, ).…”

Section: Discussionmentioning

confidence: 97%

Leucine‐induced promotion of post‐absorptive EAA utilization and hepatic gluconeogenesis contributes to protein synthesis in skeletal muscle of dairy calves

Chen

Yao

Guo

et al. 2019

Animal Physiology Nutrition

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The high rate of protein synthesis in skeletal muscle of dairy calves can benefit their first lactation even lifetime milk yield. Since the rate of protein synthesis is relatively low in the post‐absorptive state, the aim of this research was to determine whether leucine supplementation could increase the post‐absorptive essential amino acid (EAA) utilization and protein synthesis in the skeletal muscle. Ten male neonatal dairy calves (38 ± 3 kg) were randomly assigned to either the control (CON, no leucine supplementation, n = 5) or supplementation with 1.435 g leucine/L milk (LEU, n = 5). Results showed that leucine significantly increased the length and protein concentration in longissimus dorsi (LD) muscle, whereas it decreased creatinine concentration and glutamic‐oxalacetic transaminase (GOT) activity. Compared to the control group, leucine supplementation also reduced the glutamic‐pyruvic transaminase (GPT) activity. Supplementation of leucine improved the phosphorylation of mammalian target of rapamycin (mTOR), eukaryotic initiation factor 4E‐binding protein 1 (4EBP1) and substrates ribosomal protein S6 kinase 1 (p70S6K). Supplementation of leucine resulted in increased concentrations of glucose, methionine, threonine, histidine and EAAs and decreased concentration of arginine in serum. Liver glucose concentration was higher and pyranic acid was lower in LEU compared to CON. In conclusion, leucine supplementation can promote post‐absorptive EAA utilization and hepatic gluconeogenesis, which contributes to protein synthesis in skeletal muscle of dairy calves.

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Section: Discussionmentioning

confidence: 97%

Leucine‐induced promotion of post‐absorptive EAA utilization and hepatic gluconeogenesis contributes to protein synthesis in skeletal muscle of dairy calves

Chen

Yao

Guo

et al. 2019

Animal Physiology Nutrition

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“…The results of the present study are consistent with those obtained in a recent study conducted in very old mice (aged 25 months) reporting that oral gavage with a leucine‐enriched protein solution, but not a matched amount of leucine alone, stimulated MPS (Dijk et al . ). However, our results are inconsistent with the observation that an i.v.…”

Section: Discussionmentioning

confidence: 97%

“…However, we consider this doubtful because, unlike leucine, protein ingestion did increase the rate of MPS both in our middle‐aged women and the aged rats studied by Dijk et al . (). Therefore, the differences in results among studies are probably related to the dose and mode of delivery, comprising a ∼3.5 g ‘flooding’ bolus (Smith et al .…”

Section: Discussionmentioning

confidence: 97%

The muscle anabolic effect of protein ingestion during a hyperinsulinaemic euglycaemic clamp in middle‐aged women is not caused by leucine alone

Vliet

Smith

Porter

et al. 2018

The Journal of Physiology

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It has been suggested that leucine is primarily responsible for the increase in muscle protein synthesis (MPS) after protein ingestion because leucine uniquely activates the mTOR-p70S6K signalling cascade. We tested this hypothesis by measuring muscle p-mTOR , p-p70S6K and p-eIF2α , as well as protein turnover (by stable isotope labelled amino acid tracer infusion in conjunction with leg arteriovenous blood and muscle tissue sampling), in 28 women who consumed either 0.45 g protein kg fat-free mass (containing 0.0513 g leucine kg fat-free mass) or a control drink (n = 14) or 0.0513 g leucine kg fat-free mass or a control drink (n = 14) during a hyperinsulinaemic-euglycaemic clamp procedure (HECP). Compared to basal conditions, the HECP alone (without protein or leucine ingestion) suppressed muscle protein breakdown by ∼20% and increased p-mTOR and p-p70S6K by >50% (all P < 0.05) but had no effect on p-eIF2α and MPS. Both protein and leucine ingestion further increased p-mTOR and p-p70S6K , although only protein, and not leucine, ingestion decreased (by ∼35%) p-eIF2α and increased (by ∼100%) MPS (all P < 0.05). Accordingly, leg net protein balance changed from negative (loss) during basal conditions to equilibrium during the HECP alone and the HECP with concomitant leucine ingestion and to positive (gain) during the HECP with concomitant protein ingestion. These results provide new insights into the regulation of MPS by demonstrating that leucine and mTOR signalling alone are not responsible for the muscle anabolic effect of protein ingestion during physiological hyperinsulinaemia, most probably because they fail to signal to eIF2α to initiate translation and/or additional amino acids are needed to sustain translation.

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“…Kanda et al [27] visualized the peak of intramuscular and plasma leucine levels in male Sprague-Dawley rats that swam and received milk protein (whey protein and casein) at 60 min, but without significant alterations of plasma insulin concentrations. Further, Dijk et al [31] observed elevated levels of intramuscular and plasma leucine in C57/BL6RJ mice at 25 months of age after 60, 75, and 90 min of leucine-enriched whey protein gavage, but with no changes in glucose concentrations measured at 60 and 75 min. Regarding the plasma insulin levels, the authors verified higher concentrations for the animals receiving only leucine compared to the fasted mice.…”

Section: Discussionmentioning

confidence: 97%

“…At the end of the acute exercise, the animals received water or protein blend by gavage immediately or 1 h after exercise, as summarized in Figure 1. The protein blend consisted of a mix of casein (50%) and whey protein (50%) (Nutratec ® , Ribeirão Preto, SP, Brazil) with 3.1 g of protein per body weight diluted in 2.4 mL/100 g body weight [31]. Casein presented 121.95 g of protein/100 g and whey protein 133.35 g of protein/100 g. Table 1 shows the protein blend composition of amino acids in 100 g of the product label.…”

Section: Acute Resistance Exercise Protocol and Supplementationmentioning

confidence: 99%

The Combination of Fasting, Acute Resistance Exercise, and Protein Ingestion Led to Different Responses of Autophagy Markers in Gastrocnemius and Liver Samples

et al. 2020

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The present study verified the responses of proteins related to the autophagy pathway after 10 h of fast with resistance exercise and protein ingestion in skeletal muscle and liver samples. The rats were distributed into five experimental groups: control (CT; sedentary and without gavage after fast), exercise immediately (EXE-imm; after fast, rats were submitted to the resistance protocol and received water by gavage immediately after exercise), exercise after 1 h (EXE-1h; after fast, rats were submitted to the resistance protocol and received water by gavage 1 h after exercise), exercise and supplementation immediately after exercise (EXE/Suppl-imm; after fast, rats were submitted to the resistance protocol and received a mix of casein: whey protein 1:1 (w/w) by gavage immediately after exercise), exercise and supplementation 1 h after exercise (EXE/Suppl-1h; after fast, rats were submitted to the resistance protocol and received a mix of casein: whey protein 1:1 (w/w) by gavage 1 h after exercise). In summary, the current findings show that the combination of fasting, acute resistance exercise, and protein blend ingestion (immediately or 1 h after the exercise stimulus) increased the serum levels of leucine, insulin, and glucose, as well as the autophagy protein contents in skeletal muscle, but decreased other proteins related to the autophagic pathway in the liver. These results deserve further mechanistic investigations since athletes are combining fasting with physical exercise to enhance health and performance outcomes.

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Differential effects of leucine and leucine-enriched whey protein on skeletal muscle protein synthesis in aged mice

Abstract: MPS is stimulated in aged mice by leucine-enriched whey protein but not by leucine administration only. Administration of other amino acids may be required for leucine administration to stimulate muscle protein synthesis in aged mice.

Cited by 25 publications

References 45 publications

Leucine‐induced promotion of post‐absorptive EAA utilization and hepatic gluconeogenesis contributes to protein synthesis in skeletal muscle of dairy calves

Leucine‐induced promotion of post‐absorptive EAA utilization and hepatic gluconeogenesis contributes to protein synthesis in skeletal muscle of dairy calves

The muscle anabolic effect of protein ingestion during a hyperinsulinaemic euglycaemic clamp in middle‐aged women is not caused by leucine alone

The Combination of Fasting, Acute Resistance Exercise, and Protein Ingestion Led to Different Responses of Autophagy Markers in Gastrocnemius and Liver Samples

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