Bradykinin stimulates bone resorption and lysosomal-enzyme release in cultured mouse calvaria

The effect of bradykinin on bone resorption was studied in cultures of newborn-mouse calvaria. Bradykinin (0.03 microM, 1 microM) stimulated the release of 45Ca2+ from bones dissected out from mice prelabelled in vivo with 45Ca. Bradykinin (1 microM) also augmented the release of stable calcium ( 40Ca ), Pi and the lysosomal enzyme beta-glucuronidase. The stimulatory effect of bradykinin on mineral mobilization and lysosmal -enzyme release could be blocked by indomethacin. It is speculated that concomitant generation of thrombin and bradykinin in areas of trauma and inflammation may induce resorption of nearby bone tissue.