Protein Ingestion Further Augments S6K1 Phosphorylation in Skeletal Muscle Following Resistance Type Exercise in Males

Koopman, René; Pennings, Bart; Zorenc, Antoine H. G.; Loon, Luc J.C. van

doi:10.1093/jn/137.8.1880

Cited by 55 publications

(67 citation statements)

References 28 publications

(40 reference statements)

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“…This site of mTOR has been shown to be phosphorylated by p70 S6K (5). The present results agree with those of a recent study showing that protein intake together with carbohydrate before, during, and 1 h after a RE bout increased phosphorylation of p70 S6K at post 0 -4 h compared with carbohydrate only (30). Interestingly, the phosphorylation of the second isoform of S6K1, p85 S6K , clearly followed the same pattern in the present study as that of p70 S6K (see Fig.…”

Section: Discussionsupporting

confidence: 92%

“…This supports a recent finding in humans with a slightly different time scale and nutrients (30). An RE bout per se has also previously decreased the phosphorylation of 4E-BP1 shortly after exercise when protein or amino acids are not supplemented (8,9,30,36).…”

Section: Discussionsupporting

confidence: 89%

“…The phosphorylated mTOR is localized mainly close to the sarcolemmal membrane as has been shown in rodents (17,41) while rpS6 and phospho-rpS6 (p-rpS6) were mostly located very close to the nuclei as has been found earlier with p-rpS6 (30). Magnification showed that rpS6 usually surrounded the nuclei, which is theoretically optimal for efficient protein synthesis.…”

Section: Discussionsupporting

confidence: 58%

“…Ingestion of protein with carbohydrate or only branchedchain amino acids in the context of a bout of RE has been shown to increase the phosphorylation of mTOR (3), p70 S6K (26,30), and rpS6 (26,30) at 0 -4 h post-RE in humans. The effect of an intact protein source alone, such as whey, on this pathway in humans, and especially in the longer term after a bout of RE, i.e., from 12 to 72 h or after months of resistance training, is unknown.…”

mentioning

confidence: 99%

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Resistance exercise with whey protein ingestion affects mTOR signaling pathway and myostatin in men

Hulmi¹,

Tannerstedt²,

Selänne³

et al. 2009

Journal of Applied Physiology

120

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Hulmi JJ, Tannerstedt J, Selä nne H, Kainulainen H, Kovanen V, Mero AA. Resistance exercise with whey protein ingestion affects mTOR signaling pathway and myostatin in men. J Appl Physiol 106: 1720 -1729. First published March 19, 2009 doi:10.1152/japplphysiol.00087.2009.-Signaling pathways sense local and systemic signals and regulate muscle hypertrophy. The effects of whey protein ingestion on acute and long-term signaling responses of resistance exercise are not well known. Previously untrained young men were randomized into protein (n ϭ 9), placebo (n ϭ 9), and control (n ϭ 11) groups. Vastus lateralis (VL) muscle biopsies were taken before and 1 h and 48 h after a leg press of 5 ϫ 10 repetitions [resistance exercise (RE)] and after 21 wk (2 times per week) of resistance training (RT). Protein (15 g of whey) or nonenergetic placebo was ingested before and after a single RE bout and each RE workout throughout the RT. The protein group increased its body mass and VL muscle thickness (measured by ultrasonography) already at week 10.5 (P Ͻ 0.05). At week 21, the protein and placebo groups had similarly increased their myofiber size. No changes were observed in the nonexercised controls. However, the phosphorylation of p70 S6K and ribosomal protein S6 (rpS6) were increased at 1 h post-RE measured by Western blotting, the former being the greatest with protein ingestion. Mammalian target of rapamycin (mTOR) phosphorylation was increased after the RE bout and RT only in the protein group, whereas the protein ingestion prevented the post-RE decrease in phosphorylated eukaryotic initiation factor 4E binding protein 1 (p-4E-BP1). Akt phosphorylation decreased after RT, whereas no change was observed in phosphorylated eukaryotic elongation factor 2. A post-RE decrease in muscle myostatin protein occurred only in the placebo group. The results indicate that resistance exercise rapidly increases mTOR signaling and may decrease myostatin protein expression in muscle and that whey protein increases and prolongs the mTOR signaling response.hypertrophy; training; nutrition; S6K1; skeletal muscle ADEQUATE MUSCLE MASS is crucial for human well-being. It is, therefore, important to identify the mechanisms that stimulate muscle hypertrophy or prevent atrophy. The most efficient way to increase the size of a skeletal muscle is by resistance training (RT) in combination with protein-containing nutrition. Muscle hypertrophy due to RT and protein nutrition seems largely to result from cumulative acute increases in muscle protein synthesis. One resistance exercise (RE) bout can within 1 h increase muscle protein synthesis (9), which can last up to 72 h after exercise (39). Protein ingestion before or after a bout of RE has been shown to significantly enhance this response (52) and be possibly more beneficial in terms of muscle hypertrophy than nutrient ingestion at other times of day (7, 11). It would thus be important to understand how protein ingestion affects pathways regulating intracellular hypertrophy of muscle in the context ...

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Section: Discussionsupporting

confidence: 92%

Section: Discussionsupporting

confidence: 89%

Section: Discussionsupporting

confidence: 58%

mentioning

confidence: 99%

See 2 more Smart Citations

Resistance exercise with whey protein ingestion affects mTOR signaling pathway and myostatin in men

Hulmi¹,

Tannerstedt²,

Selänne³

et al. 2009

Journal of Applied Physiology

120

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“…IGF-1 and insulin enhance protein synthesis, and suppress protein degradation in skeletal muscle (4). Appropriate exercise also regulates skeletal muscle protein turnover (5,6). In addition, dietary components, particularly essential amino acids, are reported to affect muscle protein turnover (7,8).…”

mentioning

confidence: 99%

Regulation of Skeletal Muscle Protein Degradation and Synthesis by Oral Administration of Lysine in Rats

Sato

Ito

Nagasawa

2013

J Nutr Sci Vitaminol

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Summary Several catabolic diseases and unloading induce muscle mass wasting, which causes severe pathological progression in various diseases and aging. Leucine is known to attenuate muscle loss via stimulation of protein synthesis and suppression of protein degradation in skeletal muscle. The aim of this study was to investigate the effects of lysine intake on protein degradation and synthesis in skeletal muscle. Fasted rats were administered 22.8-570 mg Lys/100 g body weight and the rates of myofibrillar protein degradation were assessed for 0-6 h after Lys administration. The rates of myofibrillar protein degradation evaluated by MeHis release from the isolated muscles were markedly suppressed after administration of 114 mg Lys/100 g body weight and of 570 mg Lys/100 g body weight. LC3-II, a marker of the autophagic-lysosomal pathway, tended to decrease (p50.05, 0.08) after Lys intake (114 mg/100 g body weight). However, expression of ubiquitin ligase E3 atrogin-1 mRNA and levels of ubiquitinated proteins were not suppressed by Lys intake. Phosphorylation levels of mTOR, S6K1 and 4E-BP1 in the gastrocnemius muscle were not altered after Lys intake. These results suggest that Lys is able to suppress myofibrillar protein degradation at least partially through the autophagic-lysosomal pathway, not the ubiquitin-proteasomal pathway, whereas Lys might be unable to stimulate protein synthesis within this time frame.

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Protein and Amino Acids

Lemon

2011

Sport and Exercise Nutrition

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Protein Ingestion Further Augments S6K1 Phosphorylation in Skeletal Muscle Following Resistance Type Exercise in Males

Cited by 55 publications

References 28 publications

Resistance exercise with whey protein ingestion affects mTOR signaling pathway and myostatin in men

Resistance exercise with whey protein ingestion affects mTOR signaling pathway and myostatin in men

Regulation of Skeletal Muscle Protein Degradation and Synthesis by Oral Administration of Lysine in Rats

Protein and Amino Acids

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