Bisphosphonate treatment increases the size of the mandibular condyle and normalizes growth of the mandibular ramus in osteoprotegerin-deficient mice.

Abstract

Osteoprotegerin (OPG) is a novel secreted member of the tumor necrosis factor receptor family which plays a crucial role in negative regulation of osteoclastic bone resorption. OPG-deficient (OPG-/-) mice develop severe osteoporosis caused by significant enhancement of bone resorption by osteoclasts. We investigated the effect of administering bisphosphonate on mandibular growth and development in OPG-/- mice. Eight-week-old male OPG-/- mice and wild-type (WT) mice were administered bisphosphonate (1.25 mg/kg body weight) intraperitoneally once every 3 days for 30 days. All bone formation-related parameters and bone resorption-related parameters were significantly lower in OPG-/- mice with bisphosphonate than in those without bisphosphonate. The volume of the whole condyle and the mandibular length in OPG-/- mice without bisphosphonate were significantly smaller than in WT mice without bisphosphonate. Bisphosphonate treatment of the OPG-/- mice resulted in an increase in the volume of the mandibular condyle and mandibular ramus length. In fact, the mandibular ramus length in OPG-/- mice with bisphosphonate was similar to the length in WT mice without bisphosphonate. Histologically, the surface irregularity of the mandibular condyle that was observed in the OPG-/- mice without bisphosphonate tended to be less marked in the OPG-/- mice with bisphosphonate, and the proportion of the area of the cartilage layer relative to the whole condyle was significantly larger in OPG-/- mice with bisphosphonate than in those without bisphosphonate. In conclusion, bisphosphonate treatment results in an increase in mandibular condylar dimensions and normalization of mandibular ramus growth.

• Authors: Masakazu Kimura, Ken Miyazawa, Masako Tabuchi, Hatsuhiko Maeda, Yoichiro Kameyama, Shigemi Goto
• Journal: Calcified tissue international (Calcif Tissue Int) Vol. 82 Issue 2 Pg. 137-47 (Feb 2008) ISSN: 0171-967X [Print] United States
• PMID: 18183447 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Biomarkers
• Bone Density Conservation Agents
• Diphosphonates
• Isoenzymes
• Osteoprotegerin
• Osteocalcin
• Alkaline Phosphatase
• Acid Phosphatase
• Tartrate-Resistant Acid Phosphatase

Topics

• Acid Phosphatase (blood)
• Alkaline Phosphatase (blood)
• Animals
• Biomarkers (blood)
• Bone Density Conservation Agents (pharmacology)
• Bone Resorption (drug therapy, pathology)
• Cell Count
• Diphosphonates (pharmacology)
• Disease Models, Animal
• Gene Silencing
• Injections, Intraperitoneal
• Isoenzymes (blood)
• Male
• Mandibular Condyle (drug effects, growth & development, pathology)
• Mice
• Mice, Inbred C57BL
• Mice, Knockout
• Osteitis Deformans
• Osteocalcin (blood)
• Osteoclasts (drug effects, enzymology, pathology)
• Osteogenesis (drug effects, physiology)
• Osteoprotegerin (drug effects, genetics, metabolism)
• Tartrate-Resistant Acid Phosphatase