Cytological and functional studies of preosteoclasts and osteoclasts in the alveolar bones from neonatal XXXX using microperoxidase as a tracer.

@entity35 @entity8668
Microperoxidase (MP) was used to investigate the cytological and functional features of preosteoclasts and osteoclasts during @entity35 alveolar bone development. We observed mononuclear cells as preosteoclasts and multinuclear cells with and without @entity8668 ( @entity8668 ). In the bone facing multinuclear cells with @entity8668 as active osteoclasts, MP was extensively deposited along the external bone matrix undergoing resorption, and was phagocytosed with bone components into the vacuoles of osteoclasts. Neither preosteoclasts nor multinuclear cells without @entity8668 took up MP and bone components. Only multinuclear cells with @entity8668 seemed to resorb bone. Monocytes/macrophages (MMP) phagocytosed MP through all regions of the plasma membrane, whereas osteoclasts took up MP only through the @entity8668 which was a part of the plasma membrane. Endogenous peroxidase was detected in the MMP but not in preosteoclasts and osteoclasts. Thus, osteoclasts were considerably different from the MMP. The numbers of MMP were extremely few close to the osteoclasts, whereas moderate numbers of preosteoclasts were located close to the osteoclasts. Except for the nucleus and @entity8668 , there were many morphological similarities between preosteoclasts and osteoclasts. We therefore suggest that preosteoclasts, rather than MMP, are the precursors of osteoclasts during alveolar bone development of neonatal @entity35 .
