IGF-1 and insulin as growth hormones

Novartis Found Symp. 2004;262:56-77; discussion 77-83, 265-8.

Abstract

IGF-1 generated in the liver is the anabolic effector and linear growth promoting hormone of the pituitary growth hormone (GH). This is evidenced by dwarfism in states of congenital IGF-1 deficiency, Igf1 gene mutation/deletions or knockouts, and in Laron syndrome (LS), due to GH receptor gene mutations/deletions or IGF-1 receptor blocking. In a positive way, daily IGF-1 administration to stunted patients with LS or hGH gene deletion accelerates linear growth velocity. IGF-1 acts on the proliferative cells of the epiphyseal cartilage. IGF-1 also induces organ and tissue growth; its absence causing organomicria. Insulin shares a common ancestry with IGF-1 and with 45% amino acid homology, as well as very close relationships in the structure of its receptors and post-receptor cascade, also acts as a growth hormone. It has protein anabolic activity and stimulates IGF-1 synthesis. Pancreas agenesis causes short babies, and obese children with hyperinsulinism, with or without pituitary GH, have an accelerated growth rate and skeletal maturation; so do babies with macrosomia. Whether the insulin growth effect is direct, or mediated by IGF-1 or leptin is controversial.

Publication types

  • Review

MeSH terms

  • Animals
  • Growth Hormone / physiology*
  • Humans
  • Insulin / physiology*
  • Insulin-Like Growth Factor I / physiology*
  • Mice
  • Mice, Knockout

Substances

  • Insulin
  • Insulin-Like Growth Factor I
  • Growth Hormone