神经电刺激对大鼠脊髓钝挫伤后神经营养因子4和增殖细胞核抗原表达影响的研究

The impact of nerve electrical stimulation on the expressions of neurotrophin-4 and proliferating cell nuclear antigen after spinal cord contusion in rats

目的:探讨在电刺激干预下大鼠脊髓损伤节段神经生长因子(NT4)和增殖细胞核抗原(PCNA)的表达及对脊髓损伤的影响。方法:成年雌性SD大鼠78只,随机分为3组:假手术组(n=6)、对照组(n=36)和实验组(n=36)。Allen's法复制SD大鼠T9脊髓钝挫伤模型。实验组脊髓钝挫伤后给予夹脊穴和足三里穴位神经电刺激干预。神经行为学评分后,运用免疫组化和蛋白质印迹(Western blot)来检测NT4、PCNA的表达变化。结果:行为学观察,实验组大鼠术后1周BBB评分显著高于对照组(P<0.05),低于假手术组(P<0.05)。实验组第1—3天NT4表达显著升高(P<0.05),第7天达到峰值并且其表达明显高于对照组(P<0.05)。实验组第1—3天PCNA表达降低,第7天达到最大差异(P<0.05)。结论:电刺激干预下,脊髓组织中神经元中的NT4表达增强,电刺激能改善运动功能恢复。神经电刺激后PCNA表达减少,神经电刺激对神经干细胞的分化作用大于神经干细胞的再生增殖。

Objective： To explore the impacts of nerve electrical stimulation on the expressions of neurotrophin-4（NT4） and proliferating cell nuclear antigen（PCNA） after spinal cord contusion in SD rats. Method： Seventy-eight adult female SD rats were randomly divided into three groups： sham group （n=6）, con- trol group （n=36） and experimental group （n=36）. SD rats were prepared according to Allen＇s method for T9 spinal cord contusion. Experimental group was given Jiaji（EX-B2） point and Zusanli（ST36） point nerve electri- cal stimulation intervention after spinal cord contusion （SCC）. After neurobehavioral score assessment, immuno- histochemistry and Western blot were used to detect the expressions of NT4 and PCNA at different time and in different groups. Result： After spinal cord contusion on the l st--3rd d SD rats, BBB score increased gradually, compared with control group, on the 7th d BBB score of experimental group restored significantly（P 〈 0.05）. Immunohistochem- istry and Western blot analysis showed that the experimental group compared with control group, NT4 expres- sion raised, and reached the maximum difference until the 7th d （P〈 0.05）. PCNA expression depressed, and reached the maximum difference until the 7th d（P 〈 0.05）.Conclusion： Nerve electrical stimulation can promote the expression of NT4 but not PCNA that may create nerve regeneration microenvironment which contribute to the recovery of hindlimb motor function in rats.