Dexamethasone and 1,25(OH)2 vitamin D3 modulate the synthesis of insulin-like growth factor-I in osteoblast-like cells |
| |
| Authors: | Theresa L Chen Joanne Bednarz Mallory Raymond L Hintz |
| |
| Institution: | (1) California Biotechnology Inc., 94043 Mountain View, CA, USA;(2) Department of Pediatrics, Stanford University, 94305 Stanford, CA, USA;(3) Genetech, Inc., 460 Point San Bruno Blvd., 94080 South San Francisco, CA, USA |
| |
| Abstract: | Summary In the present study, we have shown that insulin-like growth factor-I (IGF-I) was released by primary cultures of rat osteoblast-like
(ROB) cells into the conditioned medium (CM). Dexamethasone (DEX) caused a dose-dependent inhibition of the IGF-I. At 10−8 M, DEX reduced IGF-I level to 70% of the control value (P<0.05); at 10−7 M DEX, the IGF-I level was further reduced to 60% of the control (P<0.01). The active vitamin D metabolite 1,25-dihydroxycholecalceferol 1,25(OH)2D2] slightly increased the IGF-I level, but the increase was not statistically significant. However, in combined treatments
of 10−7 M DEX and 10−8 M of 1,25(OH)2D3, the inhibition of DEX was partially antagonized by the presence of 1,25(OH)2D3. Studies with metabolically radiolabeled IGF-I by immunoprecipitation indicated the changes of IGF-I in the CM reflected
synthesis of the protein by the cells. The alteration of IGF-I level may mediate some of the actions of these steroid hormones
on bone cells. |
| |
| Keywords: | Dexamethasone Vitamin D Insulin-like growth factor-I Osteoblast-like cells |
| 本文献已被 SpringerLink 等数据库收录！ |
|
