冲击损伤后兔胫骨微结构的变化与硬骨素的表达

The relationship between the microstructure changes of rabbit tibia and the expression of sclerostin under impact load

目的研究冲击损伤后兔胫骨微结构的变化与硬骨素(sclerostin)的表达。方法以新西兰兔为实验动物,将其双侧后肢随机分成实验侧和对照侧,在实验侧胫骨近心端内侧面在0.2ms内分别施加冲击力为500N、1000N的冲击载荷,在冲击损伤后第7、14、21、28天分批处死动物,取冲击处骨组织经HE染色和sclerostin(Scl)免疫荧光染色,研究冲击损伤后骨小梁微结构变化以及sclerostin的表达。结果冲击加载后兔胫骨表面无明显变化,但损伤后骨组织微结构发生改变,骨小梁出现断裂,冲击载荷越大,微结构变化越显著。在骨组织损伤与改建过程中,sclerostin的表达也出现变化且与载荷大小和损伤程度相关,在损伤后第14天表达量达到最大值后逐渐下降。结论冲击加载会引起骨组织微结构的损伤和sclerostin表达的改变,sclerostin的表达与冲击后骨组织的损伤与改建过程相关。

Objective To study the change of microstructure of rabbit tibia and expression of sclerostin after the impact load. Methods The hind limbs of every New Zealand rabbit were divided into the experiment side and the control side randomly and the medial surfaces of proximal tibia of the experiment side were given impact load which reached 500 N and 1000 N peak impact at 0.2ms respectively. The rabbits were sacrificed at the day 7、14、21、28 after the impact, and the impacted bone tissues were sawed to study the change of microstructure of bone trabecula and expression of sclerostin due to the impact load of different magnitudes by HE and immunofluorescence staining separately. Results Obvious microstructure changes of bone tissue were found under the impact load, although there was no significant change of the tibia surface. The facture of bone trabecula turned up and the greater the impact load was, the more significant microstructure changes were. The expression of sclerostin changed and was related to the load magnitude and trauma extent. The expression reached peak at the day 14 after the impact damage and then decreased gradually. Conclusion The microstructure damage of bone tissue and the change of sclerostin expression could be caused by impact load and the expression of sclerostin was related to bone damage and remodeling after impact.