TY - JOUR
T1 - GH receptor blocker administration and muscle-tendon collagen synthesis in humans
AU - Nielsen, Rie H
AU - Doessing, Simon
AU - Goto, K.
AU - Reitelseder, S
AU - Holm, Lars
AU - Agergaard, J
AU - Schjerling, Peter
AU - Flyvbjerg, A
AU - Kjær, Michael
PY - 2011/6
Y1 - 2011/6
N2 - The growth hormone (GH)/insulin-like growth factor-I (IGF-I) axis stimulates collagen synthesis in tendon and skeletal muscle, but no studies have investigated the effect of reducing IGF-I on collagen synthesis in healthy humans. Objective: We hypothesised, that a GH blockade would decrease IGF-I and collagen synthesis in the connective tissue of skeletal muscle and tendon. Design: The study was randomised and double blinded. Participants: 20 healthy young males completed the study. Intervention: The participants were randomised to 2. weeks of GH receptor blocker supplementation (pegvisomant, 5. mg/day, n = 9) or placebo (n = 11). Main outcome measures: Serum levels of GH, IGF-I and IGF-binding protein 3 (IGFBP-3) were measured before and after pegvisomant/placebo supplementation. Fractional synthesis rates (FSR) for collagen and myofibrillar protein were determined with stable isotopes in tendon and muscle, and mRNA for collagen (COL1A1 and COL3A1) as well as IGF-I isoforms (Ea and Ec) were measured in skeletal muscle. Results: Pegvisomant decreased serum IGF-I by 20% (p < 0.01) and serum IGFBP-3 by 10% (p < 0.05). Pegvisomant supplementation had no effect on collagen synthesis in tendon and skeletal muscle, nor was muscle myofibrillar protein synthesis affected. Similarly, pegvisomant supplementation had no effect on mRNA expression of IGF-I and collagen in skeletal muscle. Conclusion: GH receptor blocker administration in healthy humans resulted in a moderate decrease in serum IGF-I. Collagen synthesis in tendon and skeletal muscle, as well as skeletal muscle IGF-I and collagen mRNA expression, was unaffected by GH receptor blocker supplementation.
AB - The growth hormone (GH)/insulin-like growth factor-I (IGF-I) axis stimulates collagen synthesis in tendon and skeletal muscle, but no studies have investigated the effect of reducing IGF-I on collagen synthesis in healthy humans. Objective: We hypothesised, that a GH blockade would decrease IGF-I and collagen synthesis in the connective tissue of skeletal muscle and tendon. Design: The study was randomised and double blinded. Participants: 20 healthy young males completed the study. Intervention: The participants were randomised to 2. weeks of GH receptor blocker supplementation (pegvisomant, 5. mg/day, n = 9) or placebo (n = 11). Main outcome measures: Serum levels of GH, IGF-I and IGF-binding protein 3 (IGFBP-3) were measured before and after pegvisomant/placebo supplementation. Fractional synthesis rates (FSR) for collagen and myofibrillar protein were determined with stable isotopes in tendon and muscle, and mRNA for collagen (COL1A1 and COL3A1) as well as IGF-I isoforms (Ea and Ec) were measured in skeletal muscle. Results: Pegvisomant decreased serum IGF-I by 20% (p < 0.01) and serum IGFBP-3 by 10% (p < 0.05). Pegvisomant supplementation had no effect on collagen synthesis in tendon and skeletal muscle, nor was muscle myofibrillar protein synthesis affected. Similarly, pegvisomant supplementation had no effect on mRNA expression of IGF-I and collagen in skeletal muscle. Conclusion: GH receptor blocker administration in healthy humans resulted in a moderate decrease in serum IGF-I. Collagen synthesis in tendon and skeletal muscle, as well as skeletal muscle IGF-I and collagen mRNA expression, was unaffected by GH receptor blocker supplementation.
U2 - 10.1016/j.ghir.2011.03.006
DO - 10.1016/j.ghir.2011.03.006
M3 - Journal article
C2 - 21498100
SN - 1096-6374
VL - 21
SP - 140
EP - 145
JO - Growth Hormone & I G F Research
JF - Growth Hormone & I G F Research
IS - 3
ER -
