地塞米松对大鼠骨骼纵向生长的直接抑制作用

Direct inhibition of dexamethasone on the longitudinal growth of bone in rats

目的探讨地塞米松是否对大鼠骨骼纵向生长具有直接抑制作用。方法选择3周龄SD雄性大鼠研究对象,实验组大鼠12只,对照组大鼠8只。实验组大鼠给予地塞米松干预,剂量为200μg/100g,连用10d。对照组大鼠注射等容积的生理盐水。测量大鼠鼻尾长和胫骨长。在距离膝关节面1cm处,离断胫骨,得到包含生长板的胫骨组织块。石蜡包埋,做胫骨冠状面切片,切片厚度5μm。Masson三染色(亮绿复染)。用leicaQWin数字图像分析软件测量生长板总厚度、增殖带、肥大带厚度。结果地塞米松处理大鼠体重、鼻尾长、胫骨长都明显落后于正常对照组大鼠;地塞米松处理大鼠生长板总厚度、增殖带、肥大带厚度都明显落后于正常对照组大鼠。结论地塞米松通过影响生长板软骨细胞直接抑制了大鼠骨骼纵向生长。

[Objective] To explore whether dexamethasone plays the direct inhibition effect on the longitudinal growth of bone in rats. [Methods] Twenty 3-week-old male weanling SD rats,were selected and were randomly divided into two groups： dexamethasone group and control group. The rats in dexamethasone group received dexamethasone （200 μg/100g body weight,） for 10 days. The rats in the control group received matching volume sodium chloride solution. All rats were determined by measuring the length of tibiae and the length of the tip of the nose to the end of the tail. The proximal tibiae were excised, fixed and decalcified, then paraffin embedded. Sections, 5 μm thick were cut. Masson trichrome staining（ light green counterstain）. Morphometric analysis was used by leica QWin. Total height of growth plate, height of proliferative zone and height of hypertrophic zone were determined. [Results] The length of tibiae and the length of the tip of the nose to the end of the tail in dexamethasone group were less than the control group. Total height of growth plate, height of proliferative zone and height of hypertrophic zone in dexamethasone group were less than the control group. [Conclusion] Dexamethasone directly inhibits the longitudinal growth of bone in rats.