Proliferation and macromolecular synthesis by rat calvarial bone cells grown in various oxygen tensions
✍ Scribed by Dr. Carl T. Brighton; Jonathan L. Schaffer; David B. Shapiro; Johnson J. S. Tang; Charles C. Clark
- Book ID
- 102916038
- Publisher
- Elsevier Science
- Year
- 1991
- Tongue
- English
- Weight
- 688 KB
- Volume
- 9
- Category
- Article
- ISSN
- 0736-0266
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✦ Synopsis
Abstract
Perinatal rat calvarial bone cells were isolated by sequential collagenase digestion and grown in oxygen tensions ranging from 1 to 60% O~2~. Cell proliferation as determined by automated cell counting and DNA content was greatest in the lower oxygen tensions (≥ 9% O~2~), whereas alkaline phosphatase activity and [^35^S]sulfate and [^14^C]proline incorporation were greatest in the higher oxygen tensions (≥ 13% O~2~). It is concluded that lower oxygen concentrations favor bone cell proliferation, whereas higher oxygen concentrations favor macromolecular synthesis. These findings, when related to the known pO~2~ of the fracture callus, suggest the following sequence of events: first, at the time of fracture an ingrowth of osteoprogenitor cells, capillary buds, and primitive mesenchymal cells occurs in the fracture site, a region of low pO~2~; second, a great increase in cellular proliferation accompanied by an initiation of macromolecular synthesis follows; finally, as the pO~2~ levels begin to increase, cellular proliferation decelerates, accompanied by an increase in macromolecular synthesis.