Post C, Freedman J
Acta Pharmacol Toxicol (Copenh). 1984 Apr;54(4):253-7. doi: 10.1111/j.1600-0773.1984.tb01926.x.
The pharmacological effect of local anaesthetic solutions in mice including their distribution within the spinal cord, were assessed following intrathecal injection at the L5-L6 interspace. A solution of 5 microliters radioactively labelled lidocaine at a concentration of 50 mg/ml or bupivacaine at 7.5 mg/ml, was used. Both drugs blocked the motor function of the hindlegs in less than 1 min. This persisted for 15.1 +/- 0.8 min. (mean +/- S.E.M.) after lidocaine and 15.2 +/- 2.7 min. after bupivacaine. The highest spinal cord concentration was adjacent to the site of injection, even if traces were present up to the lower cervical cord. The tissue concentration of bupivacaine was considerably less than that of lidocaine, despite a similar motor blockade. When the injected volume was doubled from 5 to 10 microliters, there was a tendency to a more cephalic distribution of lidocaine. When the speed of injection was increased from 2.5 sec., to 30 sec., no difference in results was seen. The drug concentration at the injection site tended to fall in animals alive until 5 min. after the injection, whereas it persisted in animals sacrificed before the intrathecal injection, suggesting that the circulatory transport is the major route of redistribution from the cord.
在小鼠L5-L6椎间隙进行鞘内注射后，评估了局部麻醉溶液在小鼠体内的药理作用，包括它们在脊髓内的分布情况。使用了浓度为50mg/ml的5微升放射性标记利多卡因溶液或浓度为7.5mg/ml的布比卡因溶液。两种药物均在不到1分钟内阻断了后肢的运动功能。利多卡因作用后持续了15.1±0.8分钟（平均值±标准误），布比卡因作用后持续了15.2±2.7分钟。即使在颈髓下部也有微量存在，但脊髓最高浓度仍位于注射部位附近。尽管运动阻滞相似，但布比卡因的组织浓度远低于利多卡因。当注射体积从5微升增加到10微升时，利多卡因有向头部更广泛分布的趋势。当注射速度从2.5秒增加到30秒时，结果未见差异。在注射后存活的动物中，注射部位的药物浓度在5分钟内趋于下降，而在鞘内注射前处死的动物中药物浓度持续存在，这表明循环转运是药物从脊髓重新分布的主要途径。
