不同时期应用甲状旁腺激素片段对糖皮质激素相关骨质疏松的影响

The effect of the application of parathyroid hormone 1-34 in different phase on glucocoticoid-induced osteoporosis

目的了解早期应用重组人甲状旁腺激素片段1-34与延迟应用对糖皮质激素诱导的骨质疏松是否存在着不同。方法选用36只日本大耳白兔,分为3个组,其中A组做为空白对照组,不施加任何处理因素,B组为早期干预组,C组为延迟干预组。B组和C组首先在4周内注射马血清10 mg/kg两次,自第5周开始每天注射一次地塞米松,第6至第9周每周注射2次地塞米松,剂量均为10mg/kg,B组从第5周开始使用地塞米松时同时给予重组人甲状旁腺激素片段1-34,20μg/天至第12周;C组第9周开始应用直到第16周,B组第12周、C组第16周处死动物,取第三腰椎进行骨形态学及DXA骨密度检查,采用photoshop软件分析骨小梁面积占整个图像面积百分比。结果骨形态学检查A组骨小梁结构最好,骨小梁占整个图像百分比为16.50%,B组次之,为8.21%,C组最差,为4.5%,3组间的差异存在着统计学意义,而骨密度检查在3组间没有差别。结论 与不使用糖皮质激素相比,早期使用和延迟应用甲状旁腺激素都可以延缓骨矿含量的流失,早期使用效果更好,但是不能完全阻止这种流失。

Objective To study the difference between the early and late intervention with parathyroid hormone （PTH） 1-34 for the treatment of glucocoid-induce osteoporosis. Methods Thirty-six Japanese rabbits were divided into 3 groups. Group A was normal control without any intervention. Group B was early intervention group. Group C was late intervention group. Rabbits in the group B and C were injected twice with horse serum in the first 4 weeks, and followed by dexamethasone （10 mg/kg） injection daily on the fifth week and twice a week from the sixth week to the eighth week. PTH 1-34 （20μg/d） was injected to the rabbits of group B daily from the sixth week to the twelfth week, and group C from the ninth week to the sixteenth week. Rabbits in Group B and C were sacrificed on the twelfth week and sixteenth week, respectively. The lumbar vertebrae 3 was used for bone histomorphometry and bone mineral density examination. The percentage of bone trabecular area to the whole image area was calculated using the Photoshop software. Results The best trabecular construction was found in group A in the bone histomorphometry examination. The percentage of trabecular area of the whole image was 16.50% in group A, 8.21% in group B, and 4.50% in group C. There were statistic differences among the 3 groups. No differences among the 3 groups were found in terms of bone mineral density. Conclusion Compared to no application of glucocoticoid hormone, either early or late intervention with PTH shows prevention from mineral loss. Early intervention produces better result. However, bone loss can not be prevented completely.