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Circadian rhythm of mechanically mediated differentiation of osteoblastsThe differential of osteoblasts in response to orthodontic pressure in the periodontal ligament of the maxillary-first-molar periodontal ligaments of 12-h-light/dark-entrained 7-wk-old male Simonsen outbred rats is measured by (H-3)-Thymidine nuclear-volume morphometry (Roberts et al., 1983) at hourly intervals throughout the circadian cycle. The results are presented in graphs and discussed. Preosteoblast large nuclei (D-cells) are found to synthesize DNA mainly in light and to divide in the following dark period, while small-nucleus osteoprogenitors (A-cells) synthesize in darkness and divide in light. These findings are seen as consistent with a model in which the sequence of proliferation and differentiation requires at least 60 h (five 12-h periods) and the shift from A to D cells lasts about 19 h.
Document ID
19850053849
Document Type
Reprint (Version printed in journal)
Authors
Roberts, W. E. (University of the Pacific San Francisco, CA, United States)
Mozsary, P. G. (University of the Pacific San Francisco, CA, United States)
Klingler, E. (Paris V, Universite Paris, France)
Date Acquired
August 12, 2013
Publication Date
January 1, 1984
Publication Information
Publication: Calcified Tissue International
Volume: 36
ISSN: 0008-0594
Subject Category
LIFE SCIENCES (GENERAL)
Funding Number(s)
CONTRACT_GRANT: NIH-DE-05135
CONTRACT_GRANT: NCA2-OR-588-002
CONTRACT_GRANT: NAGW-356
CONTRACT_GRANT: NIH-S07-RR-05301
Distribution Limits
Public
Copyright
Other