被动运动与电刺激失用性骨质疏松症大鼠模型神经生长因子基因的表达

Passive movement and electrical stimulation improve the expression of nerve growth factor in a rat model of disuse osteoporosis

背景:研究显示,被动运动与电刺激均能减缓失用性骨质疏松的症状,对骨代谢有改善作用。目的:探讨神经生长因子在失用性骨质疏松形成中的影响地位及预防过程的作用机制。方法:将50只SD大鼠按等体质量原则随机分为假手术组,坐骨神经切除组,坐骨神经切除+被动运动组(简称被动运动组),坐骨神经切除+电刺激组(简称电刺激组),坐骨神经切除+被动运动+电刺激组(简称联合干预组),每组10只。造模各组大鼠均行坐骨神经及股神经切断术(神经切断5mm),手术后24h,开始作被动运动、电刺激等治疗。假手术组与其余4组手术路径相同,但不切除坐骨神经与股神经。结果与结论:①电刺激组、联合干预组体质量高于坐骨神经切除组,差异有非常显著性意义(P<0.01)。②实时荧光定量PCR检测坐骨神经切除组神经生长因子表达低于假手术组,差异有显著性意义(P<0.05);坐骨神经切除组低于电刺激组和被动运动组,差异有显著性意义(P<0.05);联合干预组高于坐骨神经切除组,差异有非常显著性意义(P<0.01)。结果提示:①经过电刺激和被动运动干预后,大鼠胫骨组织中内源性神经生长因子基因表达水平显著提高。②提高骨组织中神经生长因子基因的表达是预防骨质疏松的重要机制之一,适宜的电刺激与被动运动均能促进这一过程。

BACKGROUND：Several studies have shown that both passive movement and electrical stimulation can relieve disuse osteoporosis symptoms and improve bone metabolism. OBJECTIVE：To explore the influence and status of nerve growth factor in the formation of disuse osteoporosis and the underlying mechanisms of prevention. METHODS：Fifty SD rats according to the principle of equal body weight were randomly divided into sham operation group （n=10） and exercise group （n=40）. Rats of the exercise group underwent sciatic nerve and femoral resection （5 mm nerve was cut） and then randomly divided into four subgroups （10 rats in each group）：sciatic nerve resection group, sciatic nerve resection＋passive movement group （passive movement group）, sciatic nerve resection＋electrical stimulation group （electrical stimulation group） and sciatic nerve resection＋massage＋electrical stimulation group （union intervention group）. After operation for 24 hours, the rats in the exercises group were given passive movement and electrical stimulation. The rats of the sham operation group had the same procedures as the other four subgroups except for sciatic nerve and femoral resection. RESULTS AND CONCLUSION：（1）Body mass of sciatic nerve resection group was lower than that of electrical stimulation and union intervention groups （P 0.01）. （2） Real-time PCR test showed that for the expression of nerve growth factor, the sciatic nerve resection group was lower than the sham operation group, and there was a significant difference between the two groups （P 0.05）; the sciatic nerve resection group was lower than electrical stimulation and passive movement groups, and the three groups had significant differences （P 0.05）; union intervention group was higher than sciatic nerve resection group, and there was a significant difference between the two groups （P 0.01）. These results suggest that after electrical stimulation and passive movement, the expression level of endogenous nerve growth factor gene in rat tibia tissues was improved remarkably. The increase of nerve growth factor gene expression in bone tissues is one of the most important mechanisms for osteoporosis prevention, and this process can be promoted by appropriate passive movement and electrical stimulation.