HUMAN CALCITONIN HAS THE SAME INHIBITORY EFFECT ON OSTEOCLASTIC BONE-RESORPTION BY HUMAN GIANT-CELL TUMOR-CELLS AS SALMON-CALCITONIN

Human calcitonin (hCT) has been reported to have a less hypocalcemizin g effect on rats and to have a lower binding affinity for tile recepto r of mouse osteoclasts than salmon CT(sCT). In this study we comparati vely examined the effect of hCT and sCT on osteoclastic bone-resorbing activity of unfractionated cells obtained from human giant cell tumor of bone and from rabbit and mouse long bones. We found that hCT had t he same inhibitory effect as sCT on the bone-resorbing activity of hum an and rabbit osteoclastic cells, but a different one on that of mouse cells. These results indicate that the activity of drugs should be as sayed using human cells if possible.