Effects of insulin-like growth factor binding protein complexes on human fibroblast growth.
Insulin-like growth factor binding protein (IGF-BP) complexes containing either IGF-I or IGF-II were purified from human plasma and coincubated with human foreskin fibroblasts. Incorporation of [3H]thymidine into fibroblasts was measured to determine the mitogenic effects of the IGF-BP complexes in comparison with purified recombinant IGF-I or IGF-II. The IGF-I-BP complex was shown to have no stimulatory activity when added to cultures at a comparable Non Suppressible Insulin-Like Activity (NSILA) dose level to that of purified recombinant IGF-I which produced maximal stimulation. In contrast, the IGF-II-BP complex produced a similar stimulatory activity to that of purified recombinant IGF-II when added at comparable NSILA doses. NSILA-p, a contaminating factor in the purified preparations of IGF-BP complexes, was shown to have no effect on fibroblast growth. This study suggests that plasma IGF binding proteins may have a differential effect on the stimulatory activities of IGFs I and II on human fibroblasts.
Tesch
G H
GH
Department of Applied Chemistry, Royal Melbourne Institute of Technology, Victoria, Australia.
Cornell
H J
HJ
Herington
A C
AC
Oakes
S
S
D002352:Carrier Proteins / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D005347:Fibroblasts / Q000166:cytology*; D006801:Humans; D018969:Insulin-Like Growth Factor Binding Proteins; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D007335:Insulin-Like Growth Factor II / Q000494:pharmacology; D011994:Recombinant Proteins
D002352:Carrier Proteins; D018969:Insulin-Like Growth Factor Binding Proteins; D011994:Recombinant Proteins; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II