The State Key Laboratory of Oral Diseases and Center of Orthognathic Surgery, West China College of Stomatology, Sichuan University, Chengdu 610041, China.
Osteoporos Int. 2012 Apr;23(4):1463-74. doi: 10.1007/s00198-011-1751-6. Epub 2011 Sep 3.
Ovariectomized (OVX) rats with tibial fracture received vehicle, ZA, PTH, or ZA plus PTH treatment for 4 and 8 weeks. Bone metabolism, callus formation, and the mass of undisturbed bone tissue were evaluated by serum analysis, histology, immunohistochemistry, radiography, micro-computerized tomography, and biomechanical test.
Previous studies have demonstrated the effect of ZA or PTH on osteoporotic fracture healing. However, reports about effects of ZA plus PTH on callus formation of osteoporotic fracture were limited. This study was designed to investigate the impact of combined treatment with ZA and PTH on fracture healing in OVX rats.
Twelve weeks after bilateral ovariectomy, all rats underwent unilateral transverse osteotomy on tibiae. Animals then randomly received vehicle, ZA (1.5 μg/kg weekly), PTH (60 μg/kg, three times a week), or ZA plus PTH until death at 4 and 8 weeks. The blood and bilateral tibiae of rats were harvested for evaluation.
All treatments increased callus formation and strength other than the control; ZA + PTH showed the strongest effects on percent bone volume (BV/TV), trabecular thickness, total fluorescence-marked callus area, and biomechanical strength. Additionally, inhibited RANKL and enhanced osteoprotegerin expression were observed in the ZA + PTH group. But no difference in bone mineral density and BV/TV of the contralateral tibiae was observed between treated groups.
Findings in this study suggested an additive effect of ZA and PTH on fracture healing in OVX rats, and this additive effect was specific to callus formation, not to undisturbed bone tissue.
去卵巢（OVX）大鼠胫骨骨折后，给予载体、ZA、PTH 或 ZA 加 PTH 治疗 4 周和 8 周。通过血清分析、组织学、免疫组织化学、放射学、微计算机断层扫描和生物力学试验评估骨代谢、骨痂形成和未受干扰骨组织的质量。
先前的研究表明 ZA 或 PTH 对骨质疏松性骨折愈合有影响。然而，关于 ZA 加 PTH 对骨质疏松性骨折骨痂形成的影响的报道有限。本研究旨在探讨 ZA 和 PTH 联合治疗对 OVX 大鼠骨折愈合的影响。
双侧卵巢切除后 12 周，所有大鼠均进行单侧胫骨横断骨折。动物随后随机接受载体、ZA（每周 1.5 μg/kg）、PTH（每周 3 次，60 μg/kg）或 ZA 加 PTH 治疗，直至 4 周和 8 周死亡。采集大鼠血液和双侧胫骨进行评估。
所有治疗均增加了骨痂形成和强度，除对照组外；ZA + PTH 对骨体积百分比（BV/TV）、小梁厚度、总荧光标记骨痂面积和生物力学强度的影响最强。此外，ZA + PTH 组观察到 RANKL 抑制和骨保护素表达增强。但治疗组对侧胫骨的骨密度和 BV/TV 无差异。
本研究结果表明 ZA 和 PTH 对 OVX 大鼠骨折愈合有相加作用，这种相加作用特定于骨痂形成，而不是未受干扰的骨组织。
