低温异丙酚对脊髓缺血再灌注损伤保护作用的实验研究

目的探讨低温异丙酚经腹主动脉灌注对兔脊髓缺血再灌注损伤的保护作用。方法健康成年新西兰大白兔60只。随机分为6组,每组10只,分别为SN组(生理盐水组)、IPN组(10%常温脂肪乳组)、PN组(50mg/kg常温异丙酚组)、SH组(4℃生理盐水组)、PH组(4℃50mg/kg异丙酚组)、IPH组(4℃10%脂肪乳组)。每组的灌注容积均为5mL/kg,灌注速度为10mL/(kg.h)。采用左肾下腹主动脉阻断法建立脊髓缺血再灌注模型,阻断开始时即泵入灌注液,30min后停止灌注并开放腹主动脉。记录术中兔生命体征及再灌注后6h、24h、48h神经行为学评分,于再灌注后48h取L4-6节段脊髓观察组织形态学改变;取T8节段脊髓组织作为正常对照(N组),测定L4-6脊髓组织中兴奋性氨基酸(EAA)及丙二醛(MDA)、超氧化物歧化酶(SOD)的含量。结果①与对照组(SN、IPN组)比较,常温异丙酚组(PN组)和低温灌注组(SH、PH、IPH组)动物神经行为学评分均明显升高,脊髓组织中EAA含量明显降低,其中以低温异丙酚组(PH组)最显著(P<0.05),SN、IPN组间差异无统计学意义。②与正常对照组(N组)比较,各实验组(SN～IPH组)L4-6脊髓组织中EAA及MDA含量明显升高,而SOD含量明显降低(P<0.05)。③与SN、IPN、SH、IPH组比较,常温和低温异丙酚组(PN、PH组)脊髓组织中SOD含量明显升高,MDA含量降低(P<0.05)。但PN、PH两组间差异无统计学意义。结论异丙酚及低温液体均能减轻脊髓缺血再灌注损伤,具有脊髓保护作用,其中低温异丙酚的保护作用更显著。

CB1 receptor localization in rat spinal cord and roots,dorsal root ganglion,and peripheral nerve

AIM:The localization of CB1 receptors in the spinal cord,spinal roots,dorsal root ganglion(DRG),and peripheral nerve of the rat was determined.METHODS:We studied the distribution of CB1 cannabinoid receptors by immunohistochemistry using an antibody raised against the N-terminal of the receptor.RESULTS:The spinal cord showed numerous transverse fibers labelled for CB1 receptors throughout and concentrated in the dorsal horn.Lightly-stained cells were observed throughout the spinal cord gray matter.The DRG also showed cells and fibers labelled for CB1 receptors.Labelled fibers were observed in both dorsal and ventral roots as well as in peripheral nerves.CONCLUSION:The presence of CB1 receptors in the DRG,the dorsal root,and the dorsal horn is in accordance with the analgesic effects of cannabinoids.The presence of labelled cells and fibers in the ventral horn and ventral root provides a substrate for cannabinoid-induced muscle relaxant and antispastic effects.