Basic fibroblast growth factor improves trabecular bone connectivity and bone strength in the lumbar vertebral body of osteopenic rats

• Published in: Osteoporosis international 2005-12, Vol.16 (12), p.1939-1947
• Main Authors: WEI YAO, HADI, Tamer, YEBIN JIANG, LOTZ, Jeff, WRONSKI, Thomas J, LANE, Nancy E
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Biomechanical Phenomena; Bone Diseases, Metabolic - diagnostic imaging; Bone Diseases, Metabolic - physiopathology; Diseases of the osteoarticular system; Elasticity; Female; Fibroblast Growth Factor 2 - metabolism; Fibroblast Growth Factor 2 - therapeutic use; Fibroblasts; Growth factors; Injections, Subcutaneous; Lumbar Vertebrae - diagnostic imaging; Lumbar Vertebrae - drug effects; Lumbar Vertebrae - metabolism; Mechanical properties; Medical sciences; Osteoclasts - diagnostic imaging; Osteoclasts - drug effects; Osteoporosis; Osteoporosis. Osteomalacia. Paget disease; Ovariectomy; Parathyroid Hormone - administration & dosage; Rats; Rats, Sprague-Dawley; Stress, Mechanical; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Surgery of the genital tract and mammary gland; Tomography, X-Ray Computed - methods; Vertebrae
• ISSN: 0937-941X; 1433-2965
• DOI: 10.1007/s00198-005-1969-2

Recently, basic fibroblast growth factor (bFGF) has been found to increase trabecular bone mass and connectivity in the proximal tibial metaphyses (PTM) in osteopenic rats. The purpose of this study was to determine the bone anabolic effects of bFGF in the lumbar vertebral body (LVB), a less loaded skeletal site with a lower rate of bone turnover than the PTM. Six-month old female Sprague-Dawley rats were ovariectomized (OVX) or sham-operated and untreated for 8 weeks to induce osteopenia. Then group 1 (sham) and group 2 (OVX) were treated subcutaneously (s.c.) with vehicle, and OVXed groups 3 and 4 were treated s.c. with PTH [hPTH (1-34) at 40 microg/kg, 5x/week] and bFGF (1 mg/kg, 5x/week), respectively, for 8 weeks. At sacrifice, the fifth LVB was removed, subjected to micro-CT for determination of trabecular bone structure and then processed for histomorphometry to assess bone turnover. The sixth LVB was used for mechanical compression testing (MTS, Bionix 858). The data were analyzed with the Kruskal-Wallis test followed by post-hoc testing as needed. After 16 weeks of estrogen deficiency, there were significant reductions in vertebral trabecular bone volume and trabecular thickness. Treatment with either bFGF or hPTH (1-34) increased BV/TV in OVX animals. Human PTH (1-34)-treated animals had significant increases in trabecular (48%) and cortical thickness (30%) and bone strength [maximum load (53%) and work to failure (175%)] compared to OVX + Vehicle animals. Treatment of osteopenic rats with bFGF increased bone volume (15%), trabecular thickness (13%), maximum load (45%) and work to failure (140%) compared to OVX + Vehicle animals (all P