Direct extraction and assay of bone tissue collagenase and its relation to parathyroid-hormone-induced bone resorption

Abstract

A method has been developed for the quantitative extraction of collagenase from as little as one 19-day-fetal-mouse calvarium. About 20-40 munits of collagenase are extracted per mg of tissue, all in a latent form that, after proper activation, shows the typical properties of mammalian collagenase. Culturing the calvaria for 2 days with parathyroid hormone (PTH) increases their procollagenase content up to 3-fold and induces bone resorption. Both PTH effects are prevented by cycloheximide, but not by indomethacin. Calcitonin inhibits resorption without affecting the PTH-induced procollagenase synthesis. The role of this synthesis is discussed in relation to the mechanisms of bone resorption.