Modulation of type beta transforming growth factor activity in bone cultures by osteotropic hormones.
AUTOR(ES)
Pfeilschifter, J
RESUMO
Type beta transforming growth factor (TGF-beta) activity was found in conditioned medium harvested from fetal rat and neonatal mouse calvariae by using the anchorage-independent growth of normal rat kidney fibroblasts as an indicator system. Calvariae incubated with parathyroid hormone, 1,25-dihydroxyvitamin D3, and interleukin 1, all factors that stimulate bone resorption showed a concentration-dependent increase in TGF-beta activity in the culture medium. Increases in TGF-beta activity persisted undiminished for 48 hr after removal of these factors. The increases in TGF-beta activity from the resorbing bone cultures were relatively greater than the increases in bone resorption. Calcitonin inhibition of bone resorption correlated with a decrease in TGF-beta activity. Thus, agents that modulate bone resorption also affect TGF-beta activity in the bone culture medium. Changes in local concentrations of TGF-beta activity by osteotropic hormones may be important in the regulation of normal bone remodeling.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=304576Documentos Relacionados
- Transforming growth factor beta inhibits bone resorption in fetal rat long bone cultures.
- Modulation of transforming growth factor type beta action by activated ras and c-myc.
- Glucocorticoid regulation of transforming growth factor beta 1 activity and binding in osteoblast-enriched cultures from fetal rat bone.
- Parathyroid hormone modulates transforming growth factor beta activity and binding in osteoblast-enriched cell cultures from fetal rat parietal bone.
- Transcriptional modulation of transin gene expression by epidermal growth factor and transforming growth factor beta.