Mixed muscle and hepatic derived plasma protein metabolism is differentially regulated in older and younger men following resistance exercise

Sheffield‐Moore, Melinda; Paddon‐Jones, Douglas; Sanford, Arthur P.; Rosenblatt, Judah; Matlock, A. G.; Cree, Melanie G.; Wolfe, Robert R.

doi:10.1152/ajpendo.00358.2004

Cited by 66 publications

(57 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Some previous data have reported elevations in postexercise mixed muscle FSR (27,78,79) and myofibrillar protein FSR measurements (71,73,101) within the early time period. Other studies, however, lend support to the fact that elevations in muscle synthesis following strenuous exercise are delayed in the recovery (81,88,96), which is a phenomenon also shown in rodents (42). Recently, Kumar et al (61) reported an improvement following the heavy loading resistance exercises similar to our protocol already in the second hour after exercise.…”

Section: Myofibrillar Protein Synthesis Ratesupporting

confidence: 79%

Contraction intensity and feeding affect collagen and myofibrillar protein synthesis rates differently in human skeletal muscle

Holm

Hall²,

Rose

et al. 2010

American Journal of Physiology-Endocrinology and Metabolism

113

139

View full text Add to dashboard Cite

(FSR), but the importance of contractile intensity and whether it interplays with feeding is not understood. This was investigated following two distinct resistance exercise (RE) contraction intensities using an intrasubject design in the fasted (n ϭ 10) and fed (n ϭ 10) states. RE consisted of 10 sets of knee extensions. One leg worked against light load (LL) at 16% of one-repetition maximum (1RM), the other leg against heavy load (HL) at 70% 1RM, with intensities equalized for total lifted load. Males were infused with [13 C]leucine, and vastus lateralis biopsies were obtained bilaterally at rest as well as 0.5, 3, and 5.5 h after RE. Western blots were run on muscle lysates and phosphospecific antibodies used to detect phosphorylation status of targets involved in regulation of FSR. The intramuscular collagen FSR was evenly increased following LL-and HL-RE and was not affected by feeding. Myofibrillar FSR was unaffected by LL-RE, whereas HL-RE resulted in a delayed improvement (0.14 Ϯ 0.02%/h, P Ͻ 0.05). Myofibrillar FSR was increased at rest by feeding (P Ͻ 0.05) and remained elevated late in the postexercise period compared with the fasting condition. The Rp-s6k-4E-binding protein-1 (BP1) and the mitogenactivated protein kinase (MAPk) pathways were activated by the HL intensity and were suggested to be responsible for regulating myofibrillar FSR in response to adequate contractile activity. Feeding predominantly affected Rp-s6k and eukaryotic elongation factor 2 phosphorylations in correspondence with the observed changes in myofibrillar FSR, whereas 4E-BP1 remained to respond only to the HL contraction intensity. Thus the study design allows us to conclude that the MAPk-and mammalian target of rapamycin-dependent signaling responds to contractile activity, whereas elongation mainly was found to respond to feeding. Furthermore, although functionally linked, the contractile and the supportive matrix structures upregulate their protein synthesis rate quite differently in response to feeding and contractile activity and intensity.gas chromatography-combustion-isotope ratio mass spectrometry; protein turnover; molecular signaling; exercise; nutrition EXERCISE INCREASES THE SYNTHESIS RATE of various skeletal muscle proteins (23,47,61,70,71,73,101), and its regulation is among others thought to be dependent on the mammalian target of rapamycin (mTOR) (30, 76) and the extracellular signal-regulated protein kinase 1/2 (49, 75, 83). Different exercise types, i.e., endurance-vs. resistance-type exercises, have been shown to exert divergent effects on muscle protein turnover and synthesis rates (95, 101). However, except from differences in exercise intensity, decisive differences in contraction type and exercise volume characterize various kinds of exercises; thus, differences in the response may be because of several varying and uncontrolled parameters. Therefore, the isolated effect of contraction intensity cannot be extracted from these studies, nor can it be done from a comparison of the number of studies invest...

show abstract

Section: Myofibrillar Protein Synthesis Ratesupporting

confidence: 79%

Contraction intensity and feeding affect collagen and myofibrillar protein synthesis rates differently in human skeletal muscle

Holm

Hall²,

Rose

et al. 2010

American Journal of Physiology-Endocrinology and Metabolism

113

139

View full text Add to dashboard Cite

show abstract

“…Although effective, the muscle growth response following repeated bouts of resistance exercise in older individuals is less than their younger counterparts (36,56). This may be due to an inability to fully stimulate muscle protein synthesis following an acute bout of resistance exercise (47). We recently showed that an acute anabolic stimulus (resistance exercise combined with essential amino acid ingestion) can stimulate muscle protein synthesis in older men; however, the response is delayed compared with young men (23).…”

mentioning

confidence: 99%

Expression of growth-related genes in young and older human skeletal muscle following an acute stimulation of protein synthesis

Drummond

Miyazaki

Dreyer

et al. 2009

Journal of Applied Physiology

View full text Add to dashboard Cite

show abstract

“…The overt causes of sarcopenia likely have a negative influence on the two primarily discussed mechanisms by which muscle mass changes: muscle protein turnover (synthesis and breakdown) and function of muscle stem cells (satellite cells) (3,54). In elderly subjects compared with young, protein synthesis has been reported as decreased and protein breakdown increased in resting muscle, and the synthetic response to resistance exercise was blunted (4,53,58). Similarly, satellite cell content in resting muscle and their ability to proliferate after exercise is decreased in elderly muscle (17,47,60).…”

mentioning

confidence: 99%

Aging alters gene expression of growth and remodeling factors in human skeletal muscle both at rest and in response to acute resistance exercise

Dennis

Przybyla

Gurley

et al. 2008

Physiological Genomics

View full text Add to dashboard Cite

The purpose of this investigation was to compare expression of genes that function in inflammation and stress, cell structure and signaling, or remodeling and growth in skeletal muscle of young (32 ± 7 yr, n = 15) and elderly (72 ± 5 yr, n = 16) healthy subjects before and after a bout of resistance leg exercises. A real-time RT-PCR method was used to screen 100 transcripts in v. lateralis biopsies obtained before and 72 h postexercise. The screen identified 15 candidates for differential expression due to aging and/or exercise that were measured quantitatively. The median levels of four mRNAs (insulin-like growth factor-1 and its binding protein IGFBP5, ciliary neurotrophic factor, and the metallopeptidase MMP2) were significantly affected by aging and were greater (1.6- to 2.3-fold, P ≤ 0.05) in the young than elderly muscle at both time points. The median levels of three mRNAs were significantly ( P ≤ 0.05) affected by exercise in the young. The metallopeptidase inhibitor TIMP1 and α-cardiac actin mRNAs increased 2-fold and 6.5-fold, respectively, and GDF8 (myostatin) mRNA decreased by 50%. However, elderly muscle did not display any significant changes in gene expression postexercise. Thus, aging muscle shows decreased levels at rest and an impaired response to exercise for a number of mRNAs for factors potentially involved in muscle growth and remodeling. Future studies must determine the functional importance of these gene expression changes to protein synthesis, satellite cell activity, and other processes that are directly involved in the mechanisms of muscle hypertrophy.

show abstract

Mixed muscle and hepatic derived plasma protein metabolism is differentially regulated in older and younger men following resistance exercise

Abstract: . Mixed muscle and hepatic derived plasma protein metabolism is differentially regulated in older and younger men following resistance exercise.

Cited by 66 publications

References 39 publications

Contraction intensity and feeding affect collagen and myofibrillar protein synthesis rates differently in human skeletal muscle

Contraction intensity and feeding affect collagen and myofibrillar protein synthesis rates differently in human skeletal muscle

Expression of growth-related genes in young and older human skeletal muscle following an acute stimulation of protein synthesis

Aging alters gene expression of growth and remodeling factors in human skeletal muscle both at rest and in response to acute resistance exercise

Contact Info

Product

Resources

About