定量半横断刀改进大鼠脊髓半横断块状缺损模型

目的研究自制定量半横断刀对大鼠脊髓半横断块状缺损模型的改进效果。方法清洁级健康成年雄性SD大鼠48只,体重220～250 g。将实验动物随机分为实验组和对照组,每组24只。实验组采用自制定量半横断刀制作脊髓半横断块状缺损模型,对照组采用眼科手术刀制作模型。观察两组大鼠术后并发症;模型制备前及制备后21 d行电生理检测;模型制备后6 h及5、28 d,光镜下观察各组脊髓半横断块状缺损边缘的组织结构;模型制备后1、3、5、7、14、21、28、35、42、56、84 d,对两组实验动物行健、患侧后肢BBB运动功能评分。结果实验组和对照组实验动物死亡率分别为0和26.67%,比较差异有统计学意义(P=0.028)。电生理检测:两组术前健侧感觉诱发电位(sensory evokedpotentials,SEP)及运动诱发电位(motor evoked potentials,MEP)潜伏期和波幅比较差异均无统计学意义(P>0.05);术后21 d,对照组MEP及SEP潜伏期明显延长,波幅降低,与术前及实验组术后21 d比较差异均有统计学意义(P<0.05);实验组组内术前及术后21 d比较差异无统计学意义(P>0.05)。组织学观察:对照组健侧脊髓损伤后6 h可观察到小血肿,5 d时见脊髓组织间隙疏松及嗜神经现象,28 d时见脊髓块状缺损边缘组织明显小空洞形成,未见正常形态神经元;而实验组5 d时未见神经元不可逆损伤,28 d时块状缺损边缘可见正常形态神经元及部分空泡样改变。运动功能评分:除实验组与对照组患侧BBB评分差异无统计学意义(P>0.05)外,其余组间或健、患侧间BBB评分比较差异均有统计学意义(P<0.05)。结论定量半横断刀制备大鼠脊髓半横断损伤模型,制作过程重复性好且制成的模型稳定,是研究脊髓半横断损伤的理想模型。

Improvement of spinal cord semi-transected and lump defect model by quantitate semi-transected blade in rats

Objective To investigate the effect of quantitative semi-transected blade on the improvement of spinal cord semi-transected and lump defect model.Methods Forty-eight male Sprague Dawley rats(weighing 220-250 g) were divided into the experimental group(n=24) and control group(n=24).The spinal cord semi-transected and lump defect model was made by self-made quantitative semi-transected blade in the experimental group,and by ophthalmic scalpel in the control group.Then,the complications were observed;the electrophysiological results were detected before modeling and at 21 days after modeling;the histological changes at margin of lump defect were observed at 6 hours,5 days,and 28 days;Basso,Beattie,and Bresnahan(BBB) scores were detected at 1,3,5,7,14,21,28,35,42,56,and 84 days after modeling.Results There was significant difference in the mortality between the experimental group(0) and the control group(26.67%)(P=0.028).Electrophysiological examination: there was no significant difference in latency and amplitude of motor evoked potentials(MEP) and sensory evoked potentials(SEP) between 2 groups at preoperation(P > 0.05);at 21 days after operation,latencies of MEP and SEP increased and the amplitude decreased in the control group,showing significant differences when compared with those in the experimental group and the preoperative values(P < 0.05),but no significant difference was seen between preoperation and postoperation in the experimental group(P > 0.05).Histological examination: in the control group,small hematoma could be observed at normal side at 6 hours after modeling,increased spaces of spinal tissue and perineural invasion were observed at 5 days,and small cavity formed without normal motoneurons at 28 days in the margin of lump defect.In the experimental group,no small hematoma could be observed at 6 hours after modeling,no inreversible injury of neuron and small cavity were observed at 5 days,and normal motoneurons were observed without small cavity at 28 days in the margin of lump defect.BBB scores: except the scores between experimental group and control group at affected side(P > 0.05),there were significant differences between groups,and between normal side and affected side for intragroup(P < 0.05).Conclusion Semi-transected and lump defect model could be set up successfully by self-made quantitate semi-transected blade,procedure is repetitive and the model is stable.This model is an ideal model for semi-transected spinal cord injury.