不同治疗周期夹脊电针对急性脊髓损伤大鼠运动功能及细胞凋亡的影响

目的:观察夹脊电针不同治疗周期对急性脊髓损伤(ASCI)大鼠运动功能及神经细胞凋亡的影响,探讨夹脊电针治疗ASCI的时效关系。方法:将雌性Wistar大鼠随机分为假手术组、模型组和夹脊电针组,每组分1、3、7、14d4个亚组,每个亚组6只。NYU打击器制备ASCI模型。夹脊电针组造模后给予夹脊电针治疗,每次30min,每日1次。用BBB评分观察ASCI大鼠肢体运动功能,HE染色观察大鼠脊髓损伤不同时间点病理形态学变化,TUNEL染色检测脊髓组织神经细胞凋亡情况。结果:模型组大鼠BBB评分较假手术组显著降低(P0.05);经电针治疗后,夹脊电针组3、7、14d组BBB评分较模型组显著升高(P0.05),且14d组评分高于3d组(P0.05)。HE染色可见,模型组1d的脊髓组织广泛出血;3d的脊髓组织结构破坏较明显,神经细胞死亡数量增多;7d的组织结构破坏严重,正常神经元减少;14d的脊髓组织形成大量空泡,炎性细胞浸润。夹脊电针组从3d开始可见神经元数量增多;7、14d两个时间点可见较大神经元,结构较好。TUNEL检测结果可见,模型组细胞凋亡数量较假手术组显著增加(P0.05);经电针治疗后,夹脊电针组3、7、14d组细胞凋亡数量显著降低(P0.05),尤以14d组降低更加明显(P0.05)。结论:夹脊电针可以显著改善ASCI大鼠运动功能及神经细胞凋亡情况,且治疗3d后即有显著疗效,并随着治疗周期的延长疗效更佳。

Effect of Electroacupuncture Intervention at Different Time-points on Locomotor Function and Apoptosis in Rats with Acute Spinal Cord Injury

Objective To observe the effect of electroacupuncture(EA)intervention at different treatment time-points on locomotor function and neuronal apoptosis in rats with acute spinal cord injury(ASCI),so as to explore its mechanism underlying improvement of ASCI.Methods Seventy-two female Wistar rats were randomly divided into sham operation,ASCI model and EA groups which were further divided into 4time-points:1,3,7and 14d(n=6at each).The ASCI model was established by weight-drop striking the exposed spinal cord(T10)using a NYU impactor device.EA(0.4-0.6mA,100Hz)was applied to bilateral"Jiaji"(EX-B 2)for 30 min,once a day for 1,3,7and 14 days,respectively in the EA group.The Basso-BeattieBresnahan(BBB)grading score was used to assess the animals' locomotor function,and H.E.staining was used to display the pathological changes of spinal cord injury at different time points.The TUNEL staining was used to detect the nerve cell apoptosis of spinal cord tissue.Results After ASCI,the BBB scores were significantly decreased and the numbers of the apoptotic nerve cells considerably increased on day 1,3,7and 14 in the model group compared with the sham operation group(P<0.05).In addition,H.E.staining showed severe damage of the spinal cord tissue,infiltration of inflammatory cells,increase of dead nerve neurons and glia cells in the number from day 3to 7,and additional increase of vacuoles on day 14.Following EA intervention,the decrease of BBB scores and the increase of apoptotic nerve cell numbers were markedly suppressed on day 3,7and 14(P<0.05).The TUNEL staining showed a decrease of the apoptotic nerve cells from day 3on and an improvement of the injuredtissue structure from day 7to 14 in the EA group.Conclusion EA stimulation of EX-B 2can significantly improve locomotor function,and lighten the spinal cord injury in ASCI rats,presenting a time-dependant tendency,which may be associated with its effect in reducing neuronal apoptosis in the spinal cord.