鞘内和侧脑室注射七氟烷对小鼠镇痛作用的比较

The comparison of the analgesia effects of intracerebroventricularly and intrathecally injected sevflurane into mice

目的比较鞘内注射和侧脑室注射七氟烷对小鼠的镇痛作用,从整体水平探讨七氟烷的镇痛作用部位。方法用热板法和扭体法观察、比较鞘内和侧脑室注射七氟烷对小鼠热板法痛阈(the pain index in hot-plate test,HPPT)及扭体次数的影响。在热板法和扭体法实验中,昆明小鼠各80只。随机分为侧脑室注药组和鞘内注药组。其中侧脑室注药组分4个亚组,每组10只,分别注射人工脑积液0.25μl/g,七氟烷0.2μl/g、0.25μl/g、0.31μl/g;鞘内注药组分为4个亚组,每组10只,分别注射人工脑脊液0.25μl/g,七氟烷0.2μl/g、0.25μl/g、0.31μl/g。结果在热板法实验中,与人工脑脊液组相比,鞘内注射七氟烷0.2μl/g、0.25μl/g、0.31μl/g能够剂量依赖性地引起HPPT的增高(P<0.01或P<0.05);侧脑室注射以上剂量的七氟烷对HPPT均无明显影响(P>0.05)。扭体法实验中,鞘内注射七氟烷0.2μl/g、0.25μl/g、0.31μl/g能剂量依赖性地减少扭体次数(P<0.05);相同剂量的七氟烷侧脑室注射对扭体次数均无明显影响(P>0.05)。结论在正常小鼠整体水平七氟烷镇痛部位主要在脊髓,脑可能不是主要镇痛部位。

Objective To compare the the analgesia effects of intracerebroventricularly and intrathecally injected sevflurane into mice and to explore the analgesia sit of sevflurane in vivo.Methods After having intracerebroventricularly or intrathecally injected different dose of sevflurane into mice,we used the hot-plate test and acetic acid-induced writhing test to investigate the analgesia effects produced by sevflurane.In the hot-plate test and acetic acid-induced writhing test,eighty mice were divided into intracerebroventricular group and intrathecal group.The two groups were divided into four sub group individually.Each subgroup had ten mice.In intracerebroventricular and intrathecal group,the mice were injected aCSF0.25μl/g,sevflurane 0.2μl/g,0.25μl/g,0.31μl/g intracerebroventricularly and intrathecally.Results In the hot-plate test,sevflurane 0.2μl/g,0.25μl/g,0.31μl/g（it） can significantly and dose-dependently increase the HPPT（the pain index in hot-plate test） of the mice（P0.05,P0.01）,while sevflurane 0.2μl/g,0.25μl/g,0.31μl/g（icv.） had little effect（P0.05）.In the acetic acid-induced writhing test,sevflurane 0.2μl/g,0.25μl/g,0.31μl/g（it） can significantly and dose-dependently decrease the writhing times（P0.01）,while sevflurane 0.2μl/g,0.25μl/g,0.31μl/g（icv） had little effect（P0.05）.Conclusion The results indicate that the spinal cord is the primary mediator of analgesia effect produced by sevflurane and the brain plays little or no role.