igf-i at 10 ( -9 ) -10 ( -7 ) m significantly increased the rate of bone matrix apposition and cdp after 24 h by 45-50 % and increased cell labeling by 8-fold in the osteoprogenitor cell zone , by 4-fold in the osteoblast cell zone , and by 2-fold in the periosteal fibroblast zone .
C0007634
cell
C0016030
fibroblast