Production of insulin-like growth factor I (IGF-I) and IGF-binding proteins by rat intestinal stromal cells in vitro

Cell Mol Life Sci. 1998 Feb;54(2):158-66. doi: 10.1007/s000180050137.


To determine if intestinal stromal cells secrete diffusible factors such as insulin-like growth factors (IGFs) capable of regulating epithelial cell growth in vitro, stromal cells were isolated by enzymatic digestion of rat intestine. Incorporation of [3H]thymidine into DNA and [14C]leucine into protein of IEC-6 cells, a model intestinal epithelial cell line, was significantly increased (two- to threefold) when the IEC-6 cells were co-cultured with stromal cells, relative to IEC-6 cells grown alone. Medium conditioned by stromal cells stimulated DNA synthesis of IEC-6 cells in a dose-dependent manner. Analysis of the conditioned medium revealed that intestinal stromal cells secreted IGF-I, but little IGF-II, in addition to an M(r) 32,000 IGF-binding protein (IGFBP-2) and an IGFBP having M(r) approximately 24,000. We conclude that rat intestinal stromal cells secrete one or more diffusible factors, which may include IGF-I and IGFBPs, capable of stimulating proliferation of IEC-6 cells in vitro.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Division / drug effects
  • Cell Line
  • Culture Media, Conditioned / pharmacology
  • DNA / biosynthesis
  • Insulin-Like Growth Factor Binding Proteins / metabolism*
  • Insulin-Like Growth Factor I / metabolism*
  • Intestines / physiology*
  • Male
  • Protein Biosynthesis
  • Rats
  • Rats, Sprague-Dawley
  • Stromal Cells / metabolism*


  • Culture Media, Conditioned
  • Insulin-Like Growth Factor Binding Proteins
  • Insulin-Like Growth Factor I
  • DNA