The effect of substrate composition and condition on resorption by isolated osteoclasts.
Osteoclasts isolated from 10-day-old rabbits were studied in a cell culture system to obtain further insight into the possible mechanisms involved in the process of bone resorption. Osteoclasts were cultured on the surfaces of devitalized mammalian bones, a composite of polycrystalline synthetic hydroxyapatite and geological single crystal hydroxyapatite. The structural interaction of osteoclasts with these various substrates was morphologically characterized by using a scanning electron microscope. Viable osteoclasts were observed to adhere and extend pseudopodia and filopodia for all cases of calcium-phosphate surfaces. However, actual resorbing process was only observed in devitalized bone surfaces. Resorption pits of various sizes were found in multiple series and showed a preference for mineral-exposed area over collagen-exposed area. The difference observed between resorption of those areas of bone surface and the failure of osteoclasts to resorb non-tissue substrates are discussed in relation to current theories of the mechanisms of mineral dissolution and resorption in mammalian calcified tissues.
Department of Oral Biology, Harvard School of Dental Medicine, Boston, MA 02115.
H
H
Shimizu
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Sakamoto
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M
Sakamoto
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DD
Lee
D000818:Animals; D001862:Bone Resorption; D002478:Cells, Cultured; D003470:Culture Media; D005260:Female; D006882:Hydroxyapatites; D008252:Macaca fascicularis; D008855:Microscopy, Electron, Scanning; D010010:Osteoclasts / Q000502:physiology*; D011817:Rabbits
D003470:Culture Media; D006882:Hydroxyapatites