补阳还五汤对大鼠缺血性脑中风损伤后轴突再生的影响

Effect of Buyang Huanwu Tang on Axonal Regeneration of Rats After Ischemic Stroke Injury

目的:探索补阳还五汤促进缺血性脑中风大鼠轴突再生和神经康复的作用。方法:SD大鼠共180只,建立大脑中动脉梗死(MCAO)模型,选取造模成功的大鼠随机分成模型组、补阳还五汤组(12 g·kg-1)和尼莫地平组(20 mg·kg-1),另设假手术组,每组28只。连续灌胃给药7 d后,断头取脑,通过TTC染色检测脑梗死率,测定脑含水量检测脑水肿程度,改良银染法观察轴突变性,免疫荧光染色观察神经微丝蛋白-200(NF-200)的表达,实时荧光定量PCR(Real-time PCR)检测排斥性导向分子a(RGMa),Ras同源酶(Rho),Rho激酶(ROCK)和脑衰反应调节蛋白2(CRMP2)的mRNA表达,并通过改良神经功能评分观察神经功能恢复情况。结果:与假手术组比较,模型组的脑梗死体积和脑含水量显著上升(P<0.01),神经功能显著下降(P<0.01),轴突变性和神经纤维损伤严重,轴突生长相关蛋白的mRNA表达异常(P<0.01);与模型组比较,补阳还五汤组和尼莫地平组的脑损伤程度明显降低,表现为脑梗死率和脑含水量显著降低(P<0.01),轴突变性减少;NF-200阳性染色增多;RGMa,Rho和ROCK的mRNA表达明显降低(P<0.05),CRMP2的mRNA表达显著升高(P<0.01),神经功能明显提高(P<0.05)。结论:补阳还五汤可通过调节轴突生长相关蛋白的mRNA表达促进缺血性脑中风损伤后轴突再生,从而改善神经功能。

Objective: To investigate the effects of Buyang Huanwu Tang(BHT) on axonal regeneration and neurological rehabilitation of the rats suffering ischemic stroke(IS). Method: A total of 180 SD rats were used to establish a middle cerebral artery infarction(MCAO)model. The animals that were successfully modeled were randomly divided into model group,BHT group(12 g·kg-1)and nimodipine group(20 mg·kg-1),and a sham group was established,with 28 rats in each group. After seven-days intragastric administration of BHT,the animals were sacrificed. TTC staining was used to test cerebral infarction. Brain water content was measured to observe cerebral edema. Bielschowsky’s silver staining and immunofluorescence were performed to observe axonal degeneration and the protein expression of neurofilament protein-200(NF-200). Quantitative real-time polymerase chain reaction(PCR)was used to analyze the mRNA expression of repulsion oriented molecule a(RGMa),Ras homologous enzyme(Rho),Rho kinase(ROCK),and collapsion response regulatory protein 2(CRMP2). Neurological function scores assay was used to examine neurological recovery. Result: Compared with sham group,the cerebral infarction volume and brain water content increased significantly(P<0.01),and motor function was markablely decreased in the model group. Axonal degeneration and nerve fiber damage were obviously observed. Also,gene expression of axon growth-related protein was deviation from normal(P<0.01). Compared with model group,the cerebral infarction rate(P<0.01),brain water content(P<0.01)and axonal degeneration of BHT group and nimodipine group were significantly reduced. The expression of NF-200 was increased. Also,the mRNA expression of RGMa,Rho and ROCK was lower(P<0.05)while the mRNA expression of CRMP2 was higher(P<0.01). And the neurological function was significantly improved(P<0.05). Conclusion: BHT can promote axon regeneration after ischemic stroke injury by regulating the mRNA expression of axon growth-related protein,thereby improving nerve function.