Growth hormone stimulates the collagen synthesis in human tendon and skeletal muscle without affecting myofibrillar protein synthesis

Simon Doessing, Katja M Heinemeier, Lars Holm, Abigail Mackey, Peter Schjerling, Michael Rennie, Kenneth Smith Petersen, Søren Reitelseder, Anne-Marie Kappelgaard, Michael Højby Rasmussen, Allan Flyvbjerg, Michael Kjaer

139 Citations (Scopus)

Abstract

In skeletal muscle and tendon the extracellular matrix confers important tensile properties and is crucially important for tissue regeneration after injury. Musculoskeletal tissue adaptation is influenced by mechanical loading, which modulates the availability of growth factors, including growth hormone (GH) and insulin-like growth factor-I (IGF-I), which may be of key importance. To test the hypothesis that GH promotes matrix collagen synthesis in musculotendinous tissue, we investigated the effects of 14 day administration of 33-50 μg kg-1 day-1 recombinant human GH (rhGH) in healthy young individuals. rhGH administration caused an increase in serum GH, serum IGF-I, and IGF-I mRNA expression in tendon and muscle. Tendon collagen I mRNA expression and tendon collagen protein synthesis increased by 3.9-fold and 1.3-fold, respectively (P < 0.01 and P= 0.02), and muscle collagen I mRNA expression and muscle collagen protein synthesis increased by 2.3-fold and 5.8-fold, respectively (P < 0.01 and P= 0.06). Myofibrillar protein synthesis was unaffected by elevation of GH and IGF-I. Moderate exercise did not enhance the effects of GH manipulation. Thus, increased GH availability stimulates matrix collagen synthesis in skeletal muscle and tendon, but without any effect upon myofibrillar protein synthesis. The results suggest that GH is more important in strengthening the matrix tissue than for muscle cell hypertrophy in adult human musculotendinous tissue.

Original languageEnglish
JournalJournal of Physiology
Volume588
Issue numberPt 2
Pages (from-to)341-51
Number of pages11
ISSN0022-3751
DOIs
Publication statusPublished - 15 Jan 2010

Keywords

  • Adult
  • Collagen
  • Cross-Over Studies
  • Double-Blind Method
  • Exercise
  • Fluoroimmunoassay
  • Human Growth Hormone
  • Humans
  • Insulin-Like Growth Factor I
  • Male
  • Muscle Proteins
  • Muscle, Skeletal
  • Protein Biosynthesis
  • RNA, Messenger
  • Reverse Transcriptase Polymerase Chain Reaction
  • Tendons
  • Time Factors

Fingerprint

Dive into the research topics of 'Growth hormone stimulates the collagen synthesis in human tendon and skeletal muscle without affecting myofibrillar protein synthesis'. Together they form a unique fingerprint.

Cite this