经寰枕后间隙蛛网膜下腔注射是脊髓损伤模型大鼠可供选择的给药方式

Subarachnoid injection via the posterior atlanto-occipital interspace is an alternative way of administration in a rat model of spinal cord injury

背景:蛛网膜下腔给药是脊髓损伤动物实验中常用的干预方式,但目前缺乏可与缓释/控释剂型配合从而减少给药次数、避免蛛网膜下腔内置管的一次性较大剂量蛛网膜下腔内给药的方法。目的:探索一种对于大鼠脊髓损伤模型可以一次性较大剂量给药的蛛网膜下腔注射方法。方法:将SD大鼠随机分为6组:脊髓损伤组采用NYU(New York University)脊髓打击器构建大鼠脊髓损伤模型,蛛网膜下腔注射组经寰枕后间隙将200μL模拟药液(生理盐水)注入蛛网膜下腔,脊髓损伤+蛛网膜下腔注射组在脊髓损伤造模后进行蛛网膜下腔注射,正常对照组无处理,蛛网膜下腔注射假手术组暴露寰枕后膜后关闭切口,脊髓损伤+蛛网膜下腔注射假手术组在脊髓损伤造模后重复蛛网膜下腔注射假手术组的操作。借助甲苯胺蓝染色探索药物注射1.5 h后在蛛网膜下腔内的弥散与分布情况,通过旷场试验、斜板试验、热板试验、体质量测量等验证是否发生蛛网膜下腔注射相关并发症。结果与结论:①各组经寰枕后间隙蛛网膜下腔注射未造成大鼠BBB评分、热板试验与斜板试验结果的异常。②蛛网膜下腔注射假手术组、蛛网膜下腔注射组大鼠术后1周时可恢复术前体质量(P>0.05),脊髓损伤组、脊髓损伤+蛛网膜下腔注射假手术组、脊髓损伤+蛛网膜下腔注射组术后2周时体质量可恢复到术前水平(P>0.05)。③术中及术后未观察到蛛网膜下腔注射引起大鼠中枢神经系统损伤的特殊征象,未见脑脊液/模拟药液外漏,术后大鼠可正常抬头,未出现精神萎靡和自残行为,蛛网膜下腔注射假手术组、蛛网膜下腔注射组未发生排尿排便障碍。④蛛网膜下腔注射后1.5 h,甲苯胺蓝溶液在大鼠蛛网膜下腔内广泛弥散,全段脊髓均有分布。⑤上述数据表明,经寰枕后间隙蛛网膜下腔注射的方法安全可靠,对脊髓损伤大鼠单次给药剂量200μL时,药物能快速到达脊髓损伤部位,引起严重并发症的风险较小,因此是大鼠脊髓损伤模型可供选择的蛛网膜下腔给药方式。

BACKGROUND:Subarachnoid injection is a commonly used intervention method in animal experiments of spinal co rd injury.However,at present,there is a lack of methods for one-time large dose of subarachnoid injection that can coope rate with sustained-release/controlled-release dosage forms to reduce the frequency of administration and avoid subarachnoid catheterization.OBJECTIVE:To investigate a method of subarachnoid injection for one-time large dose administration in a rat spinal cord injury model.METHODS:Sprague-Dawley rats were randomly divided into six groups:a spinal cord injury gro u p,a subarachnoid injection group,a spinal co rd injury+s ubarachnoid injection grou p,a subarachnoid injection sham ope ration group,a spinal cord injury+s ubarachnoid injection sham operation group.and a control group.In the spinal cord injury group,New York University spinal cord impactor was used to establish the rat spinal cord injury model.In the subarachnoid injection group,200μL of simulated liquid(stroke-physiological saline solution)was injected into the subarachnoid space of rats via the posterior atlanto-occipital interspace.Rats in the spinal cord injury+subarachnoid injection group received subarachnoid injection after modeling.Rats in the control group were given no treatment.In the subarachnoid injection sham operation group,the posterior atlanto-occipital membrane was exposed and the incision was then sutured.In the spinal cord injury+subarachnoid injection sham operation group,the posterior atlanto-occipital membrane was exposed and the incision was then sutured after modeling.Toluidine blue staining was used to detect drug diffusion and distribution in the subarachnoid space at 1.5 hou rs after injection.Open field test,inclined plane test,hot-plate test,and body mass measurement were used to ve rify the occurrence of subarachnoid injection-related complications.RESULTS AND CONCLUSION:(1)Subarachnoid injection via the posterior atlanto-occipital interspace did not cause abnormal results of Basso-BeattieBresnahan score,hot-plate test,and inclined plane test in each group.(2)Rats in the subarachnoid injection sham operation and the subarachnoid injection gro ups regained their preoperative body mass at 1 week after operation(P>0.05).Rats in the spinal co rd injury group,the spinal cord injury+subarachnoid injection sham operation group,and the spinal cord injury+subarachnoid injection group regained their preoperative body mass at 2 wee ks after ope ration(P>0.05).(3)No special signs of central nervous system injury caused by subarachnoid injection were observed intraoperatively and postoperatively.No leakage of cerebros pinal fluid/simulated solution was found.After the operation,all rats could raise their head normally,and no listlessness or self-mutilati ng behavior occurred.Rats in the subarachnoid injection sham operation and the subarachnoid injection groups did not have dysuria and dysporia,(4)At 1.5 hours after subarachnoid injection,toluidine blue solution was widely diffused in the subarachnoid space and distributed throughout the whole spinal cord.(5)The above data indicate that subarachnoid injection via the poste rior atlanto-occipital interspace is safe and reliable.A single dose of 200μL administrated can reach the injured segment of the spinal cord quickly and has a less risk of serious complications in the rat model of spinal cord injury.Therefore,it is an alternative method of subarachnoid administration in the rat model of spinal cord injury.