Expression of insulin-like growth factor I stimulates normal somatic growth in growth hormone-deficient transgenic mice

Endocrinology. 1990 Sep;127(3):1033-40. doi: 10.1210/endo-127-3-1033.


A line of transgenic mice expressing insulin-like growth factor-I (IGF-I) under the control of the mouse metallothionien-1 promoter was crossed to a line of dwarf transgenic mice lacking GH expressing cells that were genetically ablated by diphtheria toxin expression. Mice generated from this cross that carry both transgenes express IGF-I in the absence of GH. These mice grew larger than their GH-deficient transgenic littermates and exhibited weight and linear growth indistinguishable from that of their nontransgenic siblings. These results confirm the suspected role of IGF-I in mediating GH's stimulation of somatic growth, including that of long bones, and illustrates the essential role of GH and IGF-I in the modulation of postnatal growth. Analysis of differences in organ growth among these mice, however, suggests that GH and IGF-I also have growth promoting actions that are independent of one another; GH appears to be necessary for the attainment of normal liver size, while IGF-I can stimulate brain growth.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aging
  • Animals
  • Body Weight
  • Bone Development
  • Brain / growth & development
  • Diphtheria Toxin / genetics
  • Female
  • Gene Expression
  • Genotype
  • Growth Hormone / deficiency*
  • Growth Hormone / genetics
  • Growth Hormone / physiology
  • Growth*
  • Insulin-Like Growth Factor I / genetics
  • Insulin-Like Growth Factor I / physiology*
  • Liver / growth & development
  • Male
  • Metallothionein / genetics
  • Mice
  • Mice, Transgenic
  • Organ Size
  • Promoter Regions, Genetic / genetics
  • RNA, Messenger / metabolism
  • Somatomedins / physiology*


  • Diphtheria Toxin
  • RNA, Messenger
  • Somatomedins
  • Insulin-Like Growth Factor I
  • Growth Hormone
  • Metallothionein