罗哌卡因用于大鼠连续腰麻的行为学及脊髓组织钙含量变化

Behaviorial observation of ropivacaine in continuous spinal anesthesia and Ca^(2+) content of spinal cord in rats

目的:观察大鼠鞘内(蛛网膜下腔)间断给予不同浓度剂量的罗哌卡因行为学及脊髓组织钙含量变 化。方法:雄性SD大鼠24只,按改良Yaksh法置入microspinal导管至脊髓腰段8cm,随机分为4组(每组6只)。 N组(对照组)经microspinal导管注入0.9%氯化钠40μl,每间隔1.5h一次,共3次。R1,R2,R33组:注药方式同 N组,注入药物分别为0.5%,0.75%,1%罗哌卡因40μl。注药开始同期观察大鼠行为学变化,6h后取腰段脊髓测 定钙离子含量变化。结果:R1,R2,R33组注药后30s双下肢麻痹;30～90min双下肢肌张力恢复,R1组较R2组 快,R2组较R3组快,组间比较差异有显著性(P<0.05)。R3组脊髓组织钙离子含量明显高于N,R1和R23组 (P<0.05)。结论:0.5%,0.75%和1%罗哌卡因用于连续蛛网膜下腔运动神经完全阻滞时间无差异,恢复时间与 剂量有关。1%罗哌卡因能使脊髓组织钙含量明显增高。

Objective To observe the behaviour and Ca 2+content of spinal cord in rats after continuous spinal anesthesia administration of different densities and doses of ropivacaine in SD rats. Methods Twenty-four male SD rats weighing 220～280g were anesthetized.A polyurethane microspinal catheter was inserted into the lumbar subarachnoid space 8cm according to the method of Yaksh’s. The animals were randomly divided into 4 groups of 6 each:in group N the rats were given normal saline 40μl intrathecally every one and half hours for 3 times; in group R1, 0.5% ropivacaine was given; in group R2 0.75% ropivacaine and in group R3 1% ropivacaine was given. The activity of rats was observed. After 6 hours rats were perfused with 4% formamint through the ascending aorta. The rats were sacrificed and L 1~2 segment of spinal cord was immediately removed for Ca 2+ content examination. Results A total hind limbs paralysis was seen at 30 seconds and intramuscular strain gradually came back from 30 to 90 minutes after the intrathecal administration of ropivacaine in all rats. The recovery of motor black was remarkably different in group R1, R2, and R3(P<0.05). The Ca 2+content of spinal cord was significantly higher in group R3 than that in group R1 and R2 (P<0.05). Conclusion There is no significant change of motor black time and it is related to drug dose for 0.5%, 0.75% and 1% ropivacaine in continuous spinal anesthesia. 1% ropivacaine may increase Ca 2+ content in spinal cord.