异丙酚局部动脉灌注对缺血再灌注兔脊髓损伤的作用

目的通过观察脊髓组织中IL-6水平的变化及神经行为学、脊髓病理学改变,探讨异丙酚局部动脉灌注的脊髓保护作用及可能机制。方法56只健康新西兰大白兔,随机分为正常对照组(n=4)、生理盐水组(n=26)和异丙酚组(n=26)。通过腹主动脉阻断30min建立脊髓缺血再灌注损伤模型,异丙酚组经腹主动脉阻断远端持续泵注50mg/kg异丙酚,生理盐水组则泵入等量生理盐水,复灌0h及2h取L4-6节段脊髓组织测定IL-6水平,复灌48h行动物神经行为学评分,取脊髓观察病理改变。结果复灌后2h异丙酚组和生理盐水组脊髓组织内IL-6水平明显高于复灌0h(P<0.05),生理盐水组各时点均明显高于对照组和异丙酚组(P<0.05),异丙酚组与对照组差异无统计学意义;复灌后48h,异丙酚组截瘫率(30%)明显低于生理盐水组(80%)(P<0.05);异丙酚组脊髓前角正常神经元计数〔8.4(4.0～11.5)〕较生理盐水组〔2.2(0～4.3)〕明显增加(P<0.05)。结论腹主动脉阻断30min脊髓组织中IL-6水平明显升高,50mg/kg异丙酚经腹主动脉局部灌注可降低脊髓组织中IL-6水平,降低术后截瘫率,提示异丙酚局部灌注具有明显的脊髓保护作用,其机制可能与抑制局部炎性反应有关。

Effect of Propofol Aortic Infusion on Ischemia-reperfusion Spinal Co rds of Rabbits

OBJECTIVE: To reveal the mechanism of propofol aortic infusion in protecting ischemia-reperfusion spinal cords through detecting the IL-6 levels in the spinal cords and observing the neurological functioning. METHODS: Fifty six healthy New Zealand White rabbits were randomly allocated into three groups, 4 in the control group, 26 in the Saline infusion group and 26 in the Propofol infusion group. The spinal cord ischemia was induced by infrarenal aorta occlusion for 30 minutes. Propofol were infused through aorta distal to the occlude sites of the rabbits in the Propofol infusion group continuously with a pump at a rate of 50 mg/kg x 30 min. The same volume of Saline were infused in the same way and at the same rate to the rabbits in the Saline infusion group. The lumbar segments of 4-6 spinal cords were harvested and the IL-6 were examined 0 hour or 2 hours after reperfusion. The spinal cords of the rabbits in the control group were harvested right after anesthesia. Forty eight hours after reperfusion, the neurological functioning of the rabbits was assessed with the Tarlov scale system and the normal motor neurons of anterior horn of the lumbar segments of 4-6 spinal cords were counted. RESULTS: The IL-6 levels of the rabbits in the Saline infusion group were significant higher than those in the control group and the Propofol infusion group (P < 0.05). There was no significant difference in the IL-6 level between the Propofol infusion group and the control group (P > 0.05). A significant increase of IL-6 in the rabbits in the Saline infusion group and the Propofol infusion group 2 hours after reperfusion was observed (P < 0.05). The rabbits in the Propofol infusion group had less paraplegia (30%) and more normal neurons (8.4) than those in the Saline infusion group (80% and 1.9, respectively) (P < 0.05). CONCLUSION: Occlusion of aorta increases IL-6 in the injured spinal cords. Propofol aortic infusion can decrease the IL-6 level and improve the neurological functioning, which is perhaps associated with the inflammatory inhibition effect of Propofol.