Contact-mediated bone resorption by human monocytes in vitro.

Human circulating monocytes in tissue culture are capable of resorbing devitalized adult and fetal bone. An important component of this process is the adhesion of the cells to the mineralized substrate and the localized removal of matrix from beneath the attached cells. The process appears to involve both release of lysosomal enzymes onto the substrate and intracellular accumulation (transport) of resorbed matrix.