不同干预方式对失神经大鼠股骨生物力学的影响

Effect of different intervention on femoral biomechanics in denervated rats

目的观察神经生长因子、电刺激对去神经大鼠股骨生物力学的影响,为临床防治失神经废用性骨质疏松提供参考。方法 50只健康雄性大鼠随机抽签法分为A组(假手术组、10只)、B组(造模组、40只)。造模组大鼠右侧股神经和坐骨神经行切除术,然后再随机分为4组(每组10只);假手术组行同样手术,但不切除股神经和坐骨神经;去神经组大鼠每天只注射生理盐水;电刺激组每次刺激持续20分钟、每天两次,采用2 Hz频率单一方波刺激;神经生长因子组给予外源性NGF(2 U/kg·d)进行注射;联合组注射方式和刺激方式分别同神经生长因子组和电刺激组。实验30天后取材,剥离右侧股骨进行结构力学和材料力学指标检测,再进行评价。结果与假手术组相比,神经生长因子组在最大载荷(P<0.01),结构刚度、极限强度均明显降低(P<0.05);电刺激组和联合作用组指标差异不明显。与去神经组相比,电刺激组和联合作用组除在能量吸收差异不显著外,其他指标明显偏高(P<0.01)。结论去神经后股骨生物力学性能下降,电刺激和神经生长因子有利于防止或延缓骨质疏松的发生。

Objective To investigate the effect of electrical stimulation and exogenous NGF on the biomechanics of the femur in denervated rats and to provide reference to prevent and treat disused osteoporosis in the clinic.Me thods Fifty healthy male SD rats were randomly divided into group A（ sham operation group,10 rats） and group B（ model group,40 rats）.Rats in model group received excision of sciatic nerve and femoral nerve,and were further divided to 4 groups（ 10 rats in each）.Rats in sham operation group received operation without excision of sciatic nerve and femoral nerve.Denervation rats received normal saline injection daily.Electrical stimulation was processed in ES group and NGF ＋ ES group twice per day,with a 2Hz simplification square wave.Rats in NGF group received injection of 2U / kg·d exogenous NGF.Rats in combination group received the same treatment in ES group and NGF group.The right femurs were collected for structural and material examination after 30-day experiment.Re sults Compared to sham group,the maximum load,structure stiffness,and ultimate strength in the NGF group were remarkably reduced（ P〈0.01）.The difference of the indices was not significant between electrical stimulation group and the combination group.Compared to the denervation group,indices in ES group and NGF group were remarkably increased except energy absorption（ P〈0.01）.Conclusion After the denervation,the femoral mechanical property decreases.Electrical stimulation and nerve growth factor are benefitial to prevent or delay the occurrence of osteoporosis.