Micro-CT和骨力学测试观察刺老苞根皮对骨折大鼠的作用

The effects of Aralia echinocaulis Hand. Mazz on micro-CT and bone mechanics outcomes in rat fracture model

目的应用骨力学和Micro-CT技术,探讨刺老苞根皮对3月龄大鼠胫骨骨折显微结构和骨力学的影响。方法 60只SPF级3月龄SD雌性大鼠,在胫骨上打孔造模后,随机分为正常模型组、刺老苞根皮低剂量组[0.9 g/(kg·d)]、刺老苞根皮中剂量组[1.8 g/(kg·d)]、刺老苞根皮高剂量组[3.6 g/(kg·d)],每天一次,连续给药4 w。分别在给药14、21、28 d后,取右侧胫骨进行骨力学检测,取左侧胫骨进行Micro-CT扫描及三维重建。结果与模型组相比,从14 d到28 d,刺老苞根皮中剂量组、刺老苞根皮高剂量组骨的结构力学参数(弹性挠度、弹性载荷、最大挠度、最大载荷)和生物力学参数(最大应力、最大应变、弹性应力、弹性应变)明显提高(P<0.05);BV/TV、Tb.Th、Tb.V在21、28 d时刺老苞根皮中剂量组、刺老苞根皮高剂量组明显升高(P<0.05或P<0.01);Tb.Sp、SMI在21、28 d时,刺老苞根皮中剂量组、刺老苞根皮高剂量组明显低于模型组,差异有统计学意义(P<0.05或P<0.01)。结论刺老苞根皮可通过改善骨折部位骨微小结构,提高骨密度,促进骨组织结构完整性,从而提升骨的抗冲击和变形能力,使其韧性和可塑性增强,骨组织强度增加,提高胫骨骨力学性能,促进大鼠骨折修复。

Objective To investigate the effects of Aralia echinocaulis Hand. Mazz in rat fracture model using Micro-CT and bone mechanics testing. Methods Fracture model was set up in SD rats. 60 three-month-old female SD rats in SPF grade were randomly divided into model group,aqueous extract of Aralia echinocaulis Hand. Mazz low dosage group [0. 9 g/（ kg·d） ],medium dosage group [1. 8 g/（ kg·d） ]and high dosage group [3. 6 g/（ kg·d） ]. They were treated for 14,21 and 28 days. Rats in the model group were treated with distilled water,and rats in the different Aralia echinocaulis Hand. Mazz dose groups were treated with corresponding dosage once a day for 4 weeks. After 14,21 and 28 days,the right tibia of each rat was taken out for bone mechanics testing. In addition,the left tibia of each rat was taken out for Micro-CT scanning and 3 D-reconstruction. Results Compared with the model group,from the 14 th day to the 28 th day,the bone mechanics testing of right tibia of rats in the medium group and high group had significant increases in elastic deflection,elastic load,maximum deflection,maximum load,maximum stress,maximum strain,elastic stress and elastic strain（ P〈0. 05）. At the 21 st day and the 28 th day,the left tibia microscopic parameters of rats in the medium group and high group showed that BV/TV,Tb. Th,Tb. V were markedly increased（ P〈0. 05 or P〈0. 01）,whereas Tb. Sp and SMI were decreased,with statistically significant differences（ P〈0. 05 or P〈0. 01）. Conclusion Aralia echinocaulis Hand. Mazz might repair tibia micro-structure of rats,and promote bone density. It can promote bone tissue structural integrity. The bone shock resistance and deformation ability were improved. Bone strength and bone mechanical properties were increased. Aralia echinocaulis Hand. Mazz can promote the process of fracture healing in rats.