Acute loading and aging effects on myostatin pathway biomarkers in human skeletal muscle after three sequential bouts of resistance exercise

J Gerontol A Biol Sci Med Sci. 2011 Aug;66(8):855-65. doi: 10.1093/gerona/glr091. Epub 2011 Jun 10.

Abstract

To determine the influence of age and resistance exercise on myostatin pathway-related genes, younger (n = 10; 28 ± 5 years) and older (n = 10; 68 ± 6 years) men underwent four testing conditions (T1-T4). A baseline (T1) muscle sample was obtained, whereas the second and third biopsies were obtained 48 hours following the first and second training sessions (T2, T3), and a final biopsy was taken 24 hours following T3. The training sessions consisted of 3 sets of 10 repetitions (80% of one repetition maximum) on leg press, hack squat, and leg extension exercises. Follistatin (FST) messenger RNA was greater in older compared with younger men at T1 and T2 (p < .05). Follistatin-like 3 (FSTL3) messenger RNA was greater in older compared with younger men at T1 and T4 (p < .05). In older men, there was a significant decrease in myostatin (MSTN) messenger RNA at T4 (p < .05). Older men contained less active (Ser-425 phosphorylated) SMAD3 (p-SMAD3) protein than younger men at T3 and T4 (p < .05).Although it is well known that younger individuals possess a greater hypertrophic potential to resistance exercise, it appears that older individuals may paradoxically possess a more favorable resistance exercise response regarding myostatin pathway-related genes and a protein marker of pathway activity. Future research is warranted to examine the physiological significance of this age-dependent mechanism.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aging / physiology*
  • Biomarkers / metabolism
  • Computer Systems
  • Diet
  • Exercise / physiology*
  • Follistatin / metabolism
  • Gene Expression
  • Humans
  • Immunoblotting
  • Male
  • Middle Aged
  • Muscle, Skeletal / physiology*
  • Myostatin / metabolism*
  • Phosphorylation
  • Polymerase Chain Reaction
  • RNA, Messenger / metabolism
  • Resistance Training*
  • Smad3 Protein / metabolism
  • Time Factors
  • Young Adult

Substances

  • Biomarkers
  • Follistatin
  • Myostatin
  • RNA, Messenger
  • SMAD3 protein, human
  • Smad3 Protein