椎管内置入不同型号的导管对大鼠运动感觉功能及脊髓超微结构的影响

THE EFFECT OF DIFFERECT INTRATHECAL CATHETERS INSERTING ON RAT'SMOTOR AND SENSORY FUNCTION AND SPINAL UITRAMICROSTRUCTURE

目的椎管内分别置入PE10和32GPU(Polyurethane)导管,比较两种导管对大鼠运动感觉功能和脊髓超微结构的影响。方法雄性SD大鼠,随机分为A组和B组,按改良Yaksh法进行鞘内置管,A组置入PE10导管,B组置入32GPU导管。术后第1天开始连续5天通过网屏实验方法行运动功能测试;术后第1天和第6天测定评价大鼠感觉功能;术后第7天对大鼠脊髓和神经根行电镜检查。结果(1)运动功能测试结果:术后1～5天各时点两组间比较网屏试验评分有统计学差异(P<0.01),其中A组术后第5天和第1天比较结果有显著性差异(P<0.05),提示运动功能有所恢复;(2)感觉功能测试结果:术后第1天和第6天两组间比较(使用吗啡)后足热缩足反射潜伏期无统计学差异(P>0.05);(3)脊髓及神经根超微结构检查结果:B组脊髓、神经根超微结构基本正常,A组结构呈中度异常,表现为细胞核皱缩,核膜尚完整,胞核异染色质颗粒凝聚,胞浆着色加深,粗面内质网扩张,髓神经纤维部分变性,板层结构疏松,髓鞘不完整分层,内外轴膜不清晰。结论与PE10导管比较,32GPU导管对大鼠感觉运动功能和脊髓超微结构影响小,更适于作为鞘内置管的材料。

Objective To compare the effects of the PE10 catheter and 32G polyurethane catheter Inserting on rat′s motor and sensory function and spinal cord uhramicrostructure. Methods male SD rats were randomly divided into two groups, that is A and B groups. According to the method of Yaksh′s the PE10 catheter was inserted into the subarachnoid space of rat in group A , and the32G PU catheter was inserted in group B. Rats will accept the mesh exercise from 1 to 5 days of postoperation to estimate the motor function, at the same time, on postoperative 1 and 5 day the rats will accept the thermal withdraw latency （TWL）test to estimate the sensory function. On postop- erative 7th day, after anesthesia all surviving animals were perused with 4% formalin through the ascending aorta and then we removed the lumbar enlargement of spinal cord for electron microscopic examination. Results （ 1 ） A-bout motor function： There had significant difference between two groups about mesh exercise score during 1-5days of postoperation（ p 〈0.01 ）. Moreover, in group A there had significant difference between the 5th and the 1 st day （p 〈 0.05 ）. （2）About sensory function： On postoperative 1 st and 5th day, after intrathecal injection morphine 20μg there had no significant difference about TWL between two groups （ p 〉 0.05 ）. （3） Spinal ultramicro- structure Results The ultramicrostructure of spinal cord and nerve roots in group B were normal, while there were middle abnormality in group A, showed as. nucleolus psychosis, hetero - chromatin condensed and endoplasmic reticulum underwent swelling and vacuole degeneration, but karyotheca is still intact. The neurolemnia of the nerve root became loose and were stratified and partly disrupted. Some of them express demyelization. Conclusion Com- pared with PE10 catheter, the 32G PU catheter has little effects on motor and sensory function and spinal ultrami- crostructure, so that it is suitable for intrathecal catheterization.