Stimulatory effects of parathyroid hormone and 1,25-dihydroxyvitamin D3 on insulin-like growth factor-binding protein-5 mRNA expression in osteoblastic UMR-106 cells: the difference between transient and continuous treatments.
The transient treatment with parathyroid hormone (PTH) for 12 h, followed by its removal for 36 h, stimulated insulin-like growth factor-binding protein (IGFBP)-5 mRNA expression more strongly than the continuous treatment for 48 h in osteoblastic UMR-106 cells. The transient but not continuous treatment with A23187 also stimulated it. In contrast, 1,25-dihydroxyvitamin D3 stimulated it, irrespective of the treatment design. IGFBP-5 stimulated type-1 procollagen mRNA expression. The present study first indicated that the transient treatment with PTH more effectively stimulated IGFBP-5 mRNA expression than its continuous treatment partly via an increase in intracellular calcium and suggested that IGFBP-5 might be involved in the anabolic action of PTH in bone.
Nasu
M
M
Department of Medicine, Kobe University School of Medicine, Japan.
Sugimoto
T
T
Chihara
K
K
D000818:Animals; D002117:Calcitriol / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D018975:Insulin-Like Growth Factor Binding Protein 5 / Q000235:genetics*; D010006:Osteoblasts / Q000187:drug effects / Q000378:metabolism*; D010281:Parathyroid Hormone / Q000494:pharmacology*; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D015398:Signal Transduction / Q000235:genetics; D014407:Tumor Cells, Cultured
D018975:Insulin-Like Growth Factor Binding Protein 5; D010281:Parathyroid Hormone; D012333:RNA, Messenger; D002117:Calcitriol