IMMUNOCYTOCHEMICAL LOCALIZATION OF COLLAGENASE IN ISOLATED MOUSE BONE CELLS

Abstract

Immunoreactive collagenase was localized -in isolated mouse bone cells by indirect immunofluorescent and immunoperoxidase antibody techniques using goat antimouse bone collagenase antibody. Immunoreactive collagenase was localized primarily in cells with osteoblastic characteristics (osteoblast-like cells) based on biochemical parameters; i.e., cAMP production and alkaline and acid phosphatase activity changes in response to parathyroid hormone. There was no collagenase immunofluorescence in cell populations rich in osteoclastic cells. Both parathyroid hormone and heparin appeared to stimulate the synthesis and/or release of immunoreactive collagenase by isolated osteoblast-like cells. These findings were consistent with the results of our biochemical studies (subsequent paper) using the same isolated bone cell preparations. Collagenase immunofluorescence of isolated bone cells was observed initially as fine granular fluorescence packed at perinuclear regions. This fine granular fluorescence then appeared to diffuse through the cytoplasm and to be secreted extracellularly.