甲状旁腺素（1-34）对卵巢切除大鼠腰椎间盘退行性变的影响

Effect of parathyroid hormone （1-34） on lumbar intervertebral disc degeneration in ovariectomized rats

目的：探讨甲状旁腺素（PTH，1-34）对卵巢切除大鼠腰椎间盘退变的治疗作用及其作用机制。方法：雌性SD大鼠，随机分为假手术组、卵巢切除＋生理盐水组（生理盐水组）、卵巢切除＋甲状旁腺素（1-34）组（甲状旁腺组）。卵巢切除术后8周，甲状旁腺组大鼠皮下注射PTH（1-34），生理盐水组大鼠给予等剂量生理盐水。卵巢切除术后20周处死大鼠并收集标本。对第2-3腰椎椎体进行骨密度测量。对第4-5腰椎及椎间盘进行HE染色及免疫组织化学方法检测，并根据组织学评分系统对腰椎间盘的退变程度进行评分。结果：生理盐水组大鼠第2-3腰椎椎体骨密度低于甲状旁腺组及假手术组；生理盐水组大鼠第2-3腰椎椎间盘组织学评分高于甲状旁腺组及假手术组；免疫组织化学显色，甲状旁腺组与假手组大鼠椎间盘Ⅰ、Ⅱ胶原表达差异无统计学意义。结论：皮下每周注射甲状旁腺素（1-34）20μg／kg能减轻去势大鼠椎间盘的退变，使椎体骨密度增加，Ⅰ、Ⅱ胶原的表达增加。

Objective： To investigate the effects and mechanism of parathyroid hormone （1-34） on lumbar intervertebral disc in ovariectomized rats. Methods： 3-monthold female Sprague-Dawley rats were randomized into three groups. Ovariectomy was performed in OVX＋NS group and OVX＋PTH group, and a Sham surgery was performed in the Sham group. Four weeks after ovariectomy,the rats in OVX＋PTH group and OVX＋NS group received injection subcutaneously of 20 μg/kg PTH（1-34） or saline respectively every week. The lumbar vertebra were harvested 20 weeks after ovariectomy and underwent bone mineral density （BMD） measurement, hematoxylin and eosin staining and histochemistry analysis. Results： The bone mineral density of L2-3 vertebra in the OVX＋NS group was significantly lower than that in the Sham group and OVX ＋PTH group; the histological score of L2-3 vertebra was significantly higher in OVX＋NS group than that in the Sham group and OVX＋PTH group. There was no significant difference in the immunostaining expressions of collagen I and collagen Ⅱ between the Sham group and OVX＋PTH group. Conclusion： Subcutaneous injection of parathyroid hormone （1-34） （20 μg · kg^-1 ·weekl） for twelve weeks can delay the degenerated process of intervertehral discs in ovariectomized rats.