Serum growth hormone-binding protein (GHBP) activity is decreased by administration of insulin-like growth factor I in three Laron syndrome siblings with normal GHBP

Proc Soc Exp Biol Med. 1994 Jul;206(3):324-7. doi: 10.3181/00379727-206-43769.

Abstract

Three Laron Syndrome (LS) siblings with a post growth hormone (GH) receptor defect for insulin-like growth factor-I (IGF-I) synthesis were found to have serum GH-binding protein (GHBP) levels normal for age. Treatment with recombinant IGF-I (150 micrograms/kg/day) decreased serum GHBP activity to 62% of the basal value (P < 0.001) in two of the sibs in 1 week and in the third sib after 3 months of therapy. Scatchard analysis of the binding of [125I]human GH (hGH) to GHBP in patients' sera before and during therapy revealed affinity constants Ka = 1.55-1.80 x 10(9) M-1, similar to that of sera from healthy subjects. Variations in binding are due to changes in the binding capacity. IGF-I may be a regulatory factor for serum GHBP activity in man.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carrier Proteins / blood*
  • Child
  • Child, Preschool
  • Female
  • Growth Hormone / blood
  • Humans
  • Insulin-Like Growth Factor I / therapeutic use*
  • Kinetics
  • Male
  • Protein Binding
  • Receptors, Somatotropin / deficiency*
  • Receptors, Somatotropin / genetics
  • Recombinant Proteins / therapeutic use
  • Syndrome

Substances

  • Carrier Proteins
  • Receptors, Somatotropin
  • Recombinant Proteins
  • Insulin-Like Growth Factor I
  • Growth Hormone
  • somatotropin-binding protein