Insulin-like growth factor I enhances the formation of type I collagen in hydrocortisone-treated human osteoblasts.
We have studied the effect of insulin-like growth factor I (IGF-I) on the formation of osteocalcin and type I collagen in isolated human osteoblasts. IGF-I at and above 0.1 nM stimulated the formation of type I collagen as measured by the type I procollagen carboxyterminal peptide (PICP), in human osteoblasts, incubated for 72 hrs in serum free conditions. The secretion of osteocalcin was not affected by IGF-I while 1,25(OH)2vitamin D3 significantly enhanced the formation of osteocalcin. When human osteoblast-like cells were incubated with hydrocortisone (1 microM), a significant decrease in the release of both PICP and osteocalcin was seen. Addition of IGF-I to human osteoblasts also treated with hydrocortisone normalized the PICP-formation but did not affect the suppressed osteocalcin-formation. These data indicate that IGF-I reverses selective effects of hydrocortisone on bone.
Jonsson
K B
KB
Department of Internal Medicine, University Hospital, Uppsala, Sweden.
Ljunghall
S
S
Karlström
O
O
Johansson
A G
AG
Mallmin
H
H
Ljunggren
O
O
D002117:Calcitriol / Q000494:pharmacology; D002478:Cells, Cultured; D004357:Drug Synergism; D006801:Humans; D006854:Hydrocortisone / Q000494:pharmacology*; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D010006:Osteoblasts / Q000187:drug effects / Q000378:metabolism*; D011347:Procollagen / Q000096:biosynthesis*
D011347:Procollagen; D007334:Insulin-Like Growth Factor I; D002117:Calcitriol; D006854:Hydrocortisone