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Proliferation and macromolecular synthesis by rat calvarial bone cells grown in various oxygen tensions
Author(s) -
Brighton Carl T.,
Schaffer Jonathan L.,
Shapiro David B.,
Tang Johnson J. S.,
Clark Charles C.
Publication year - 1991
Publication title -
journal of orthopaedic research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.041
H-Index - 155
eISSN - 1554-527X
pISSN - 0736-0266
DOI - 10.1002/jor.1100090610
Subject(s) - oxygen , macromolecule , chemistry , microbiology and biotechnology , biophysics , biochemistry , biology , organic chemistry
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.