鞘内注射罗哌卡因对大鼠脊髓的神经毒性

目的 评价鞘内注射罗哌卡因对大鼠脊髓的神经毒性.方法 取鞘内置管成功的雄性SD大鼠60只,体重180～220 g,随机分为6组(n=10),分别鞘内注射0.75%布比卡因17 μl(A1组)、0.75%罗哌卡因20μl(A2组)、1%罗哌卡因15μl(A3组)、0.75%布比卡因34μl(B1组)、0.75%罗哌卡因40μl(B2组)和1%罗哌卡因30μl(B3组).注药后记录出现双后肢瘫痪时间和运动功能恢复情况.注药后6 h取腰膨大处脊髓,采用免疫组织化学法计数fos蛋白阳性细胞,测定fos蛋白表达;采用RT-PCR技术测定c-fos mRNA表达;透射电镜观察脊髓超微结构.结果 与A1组比较,A3组和B1组出现双后肢瘫痪时间缩短,B1组fos蛋白阳性细胞计数和fos蛋白表达升高(P<0.01);与A2组比较,A3组和B2组出现双后肢瘫痪时间缩短,B2组fos蛋白阳性细胞计数和fos蛋白表达升高(P<0.01);与A3组、B1组和B2组比较,B3组出现双后肢瘫痪时间缩短,双后肢运动功能恢复率降低,fos蛋白阳性细胞计数、fos蛋白表达和c-fos mRNA表达均升高(P<0.01),脊髓损伤加重.结论 鞘内注射0.75%罗哌卡因和小剂量1%罗哌卡因对大鼠无脊髓神经毒性;鞘内注射大剂量1%罗哌卡因对大鼠可产生脊髓神经毒性,但比大剂量0.75%布比卡因脊髓神经毒性小.

Neurotoxic effects of intrathecal ropivacaine on spinal cord in rats

Objective To evaluate the neurotoxic effects of intrathecal (IT) ropivacaine on the spinal cord in rats.Methods Sixty healthy male SD rats weighing 180-220 g in which IT catheters were successfully placed according to Yaksh TL were randomly divided into 6 groups (n = 10 each). The animals received 0.75% bupivacaine 17 μl (group A1); 0.75% ropivacaine 20 μl (group A2)and 1% ropivacaine 15 HI (group A3 ) IT respectively. The volumes of IT bupivacaine/ropivacaine were doubled in group B : 075 % bupivacaine 34 μl(group B1); 0.75% ropivacaine 40 μl (group B2) and 1% ropivecaine 30 μl (group B3). The onset time of bilateral hindlimb paralysis and recovery time were recorded. The animals were killed at 6 h after IT bupivecaine/ropivacaine injection. The lumbar segment of the spinal cord was removed for microscopic examination with electron microscope and determination of expression of c-los mRNA (by RT-PCR) and protein (by immuno-histochemistry) .Results The onset time of hindlimb paralysis was shorter in group A3 and B1 and the number of los-protein positive cells and the expression of los-protein were significantly higher in. group B1 than in group A1.The onset time of hindlimb paralysis was shorter in group A3 and B2 and the number of los-protein positive cells and the expression of fos-protein were significantly higher in group B2 than in group A2. The onset time of paralysis was shorter, the rate of recovery of motor function of bilateral hindlimbs was lower, the number of fos-protein positive cells and expression of los-protein and mRNA were significantly higher and spinal cord injury was severer in group B2 than in group A3, B1 and B2. Conclusion 0.75 % and small dose of 1% ropivacaine administered 1T do not produce neurotoxicity to the spinal cord while large dose of 1% ropivecaine can produce neurotoxicity which is less severe than that produced by large dose of 0.75 % bupivacaine.