IN-VIVO STIMULATION OF ENDOSTEAL BONE-FORMATION BY BASIC FIBROBLAST GROWTH-FACTOR IN RATS

Intravenous administration of human basic fibroblast growth factor (bF GF) for 2 weeks stimulated osteoblast proliferation and new bone forma tion in various skeletal bones in young and aged rats at dosage levels of 0.1 mg/kg/day and greater. Morphometry of the soft X-ray radiogram s of cross sections of the tibia indicated about a 20% increase in the calcified bone area of the diaphysis at 0.1 mg/kg/day. The Ca and hyd roxyproline contents showed statistically significant increases at thi s dosage. The new bone formation was found only on the endosteal side, and no periosteal bone formation was found. Similar systemic osteogen ic potential was seen after intravenous administration of other growth factors of the FGF family, human acidic FGF and human heparin-binding secretory transforming protein-1. The above results suggest a potenti al therapeutic role for these growth factors in bone-loss diseases suc h as osteoporosis.