Serum growth hormone binding protein activity in healthy neonates, children and young adults: correlation with age, height and weight

Clin Endocrinol (Oxf). 1989 Sep;31(3):295-303. doi: 10.1111/j.1365-2265.1989.tb01253.x.

Abstract

Serum growth hormone binding protein (GHBP) activity was estimated in healthy neonates (n = 6), children and adolescents (n = 97) and young adults (n = 19). GHBP activity was measured by incubating 125I-hGH (human growth hormone) (approximately 25,000 c.p.m.) with serum (100 microliters) in the presence and in the absence of excess unlabelled hGH, followed by separation of specifically bound 125I-hGHBP complexes from free 125I-hGH by gel filtration on Ultrogel AcA44 minicolumns. The results are expressed as the percentage specific binding relative to an adult reference serum (%RSB), after correction for endogenous hGH of the unknown serum. The between-assay coefficients of variation for two sera of %RSB activity of 51.2 and 115.4% were 6.0 and 7.0% respectively. In neonates, low values of serum GHBP were found (%RSB = 27.1 +/- 5.0 SEM) followed by a major rise during the first 6 years of life to a mean value (%RSB = 68.3 +/- 4.1 SEM) which more than doubled that of neonates. Thereafter, values rose progressively throughout childhood and puberty to reach maximum values in young adults (%RSB = 95.0 +/- 3.1 SEM). A novel observation was that serum GHBP activity correlated significantly with height standard deviation score (SDS) (males: r = 0.77, P less than 0.001; females: r = 0.56, P = 0.01) and weight SDS (P less than 0.001) for both sexes before puberty. During puberty GHBP correlated only with weight SDS in males (r = 0.60, P less than 0.01). In all age groups studied, no correlation could be found between serum GHBP and height velocity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aging*
  • Analysis of Variance
  • Carrier Proteins / blood*
  • Child
  • Child Development
  • Child, Preschool
  • Female
  • Humans
  • Infant
  • Infant, Newborn
  • Male
  • Puberty / physiology
  • Sex Factors

Substances

  • Carrier Proteins
  • somatotropin-binding protein