Objective:To test the therapeutic effect of PAP on experimental fracture and its mechanism.Methods:Effect of PAP on the incorporation of 〔 3H〕 TdR into DNA syntheses in the cells of rabbits costal cartilage and human embryonic joint as well as osteoblast precursor cells of embryonic chick calvaria in vitro and effect of PAP on the experimental radius fracture in rats in vivo were observed.Results:PAP of 10~50 μg·ml -1 showed mitogenic activities and significant promotion of DNA syntheses for vari...