The expression of insulin-like growth factor-I mRNA and polypeptide in rat osteoblasts with exposure to parathyroid hormone / 中华医学杂志(英文版)
Chinese Medical Journal
; (24): 1916-1922, 2003.
Article
in En
| WPRIM
| ID: wpr-235852
Responsible library:
WPRO
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the insulin-like growth factor-I (IGF-I) gene and polypeptide expression in cultured rat osteoblast (ROB) and the role of IGF-I in mediating the cell-to-cell communication by mimicking the pharmacokinetics of parathyroid hormone (PTH).</p><p><b>METHODS</b>The ROB was cultured with three kinds of treatment: (1) Control (Ctr), the cells were cultured without PTH during the first 6 hours and the subsequent 42 hours in a 48-hour cycle; (2) Intermittent exposure to PTH (Itm), the cells were cultured with PTH during the first 6 hours, but without PTH in the subsequent 42 hours; and (3) Continuous exposure to PTH (Ctu), the cells were cultured with PTH during the first 6 hours and the subsequent 42 hours.</p><p><b>RESULTS</b>The bone-forming activities of ROB were increased in Itm and inhibited in Ctu. The IGF-I mRNA content in Itm cells was elevated only during the first 6 hours and that in Ctu cells was elevated at any time during an incubation cycle. The free IGF-I concentration in the medium of Itm cells was generally higher and that of the Ctu cells was generally lower compared with those of the Ctr cells. The IGF-I antibody significantly reduced the alkaline phosphatase activity within the cells of Ctr and Itm.</p><p><b>CONCLUSIONS</b>PTH rapidly and constantly stimulates the IGF-I gene transcription of osteoblast. There was an obvious discrepancy between the IGF-I mRNA content within the osteoblast and the free IGF-I level around the osteoblast in either mode of PTH action. The IGF-I might be important for osteoblast-osteoblast communication and bone-forming activity, not only in intermittent PTH administration, but also in the physiological functioning of osteoblasts.</p>
Full text:
1
Database:
WPRIM
Main subject:
Osteoblasts
/
Parathyroid Hormone
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Peptides
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Pharmacology
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Physiology
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Transcription, Genetic
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RNA, Messenger
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Insulin-Like Growth Factor I
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Gene Expression
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Cells, Cultured
Limits:
Animals
Language:
En
Journal:
Chinese Medical Journal
Year:
2003
Document type:
Article