STIMULATION OF BONE-FORMATION BY INTRAOSSEOUS INJECTION OF BASIC FIBROBLAST GROWTH-FACTOR IN OVARIECTOMIZED RATS

The effect on intraosseous bone formation of a single local injection of recombinant human basic fibroblast growth factor into trabecular bo nes was examined in ovariectomised osteoporotic mts. Fibroblast growth factor (400 mu g), or the vehicle alone, was injected into the ilium at 16 weeks after ovariectomy or a simulated operation. Bone mineral d ensity in the ovariectomised rats increased to a level similar to the Latter at 2 weeks and reached a maximum at 8 weeks. After 8 weeks, BMD decreased slowly and the value at 24 weeks was still higher than that in the ovariectomised rats. Fibroblast growth factor stimulated osteo id formation in the first 2 weeks, bone volume reaching a peak at 8 we eks. From 8 to 12 weeks, bone resorption increased, resulting in decre ases in bone volume to the levels of the group with simulated operatio ns at 24 weeks. Structural analysis at 8 and 24 weeks showed that ovar iectomy decreased the continuity of trabeculae and the injection of fi broblast growth factor restored it to levels higher than, or equal to, those who had the simulated operation. The present study demonstrated that intraosseous fibroblast growth factor given to ovariectomised ra ts restored bone volume and quality to the Levels of the rats who had a simulated operation only.