脊髓神经元凋亡在鞘内注射血小板活化因子诱发大鼠痛敏中的作用

目的：探讨脊髓神经元凋亡在鞘内注射血小板活化因子（PAF）诱发大鼠痛敏中的作用。方法鞘内置管成功的雄性 Sprague-Dawley 大鼠60只,随机分为2组：对照组,30只,鞘内注射人工脑脊液（arti-ficial cerebral spinal fluid,ACSF）10μl；PAF 组,30只,鞘内注射 PAF 10μg,溶解于10μl 人工脑脊液；分别于鞘内给药前1 d、给药后1、3、5、7、14 d 分别测定机械痛阈（PWMT）和热痛阈（PWTL）。取 L4-6脊髓,采用TUNEL 法观察脊髓神经元凋亡。结果鞘内注射血小板活化因子（PAF）可诱发出大鼠机械性触诱发痛和热痛觉过敏。PAF 组术后1 d 脊髓中开始有少量凋亡神经元出现,凋亡指数于术后3 d 开始迅速增加,术后5 d 达峰值,与对照组比较,有显著性差异（P 〈0.01）。结论鞘内注射 PAF 诱发大鼠触觉异常痛敏和热痛敏,脊髓神经元凋亡可能参与了鞘内注射 PAF 大鼠痛敏的形成。

Effects of platelet-activating factor administered intrathecally on the expression of neuronal apoptosis in spi-nal cord of rats

Objective To investigate the roles of neuronal apoptosis in development of tactile allodynia and thermal hyperalgesia induced by platelet-activating factor administered intrathecally.Methods 60 Sprague-Dawley rats with intrathecal PE-10 catheters were randomly divided into two groups：control（artificial cerebral spinal fluid,10 μl）group,PAF （10 μg,dissolved in 10 μl ACSF）group.Paw withdrawal mechanical threshold and thermal latency were measured at-1 ,1 ,3,5,7 and 14 days after surgery .Changes of apoptosis of spinal neuron were observed by TUNEL.Results Intrathecally administered PAF induced development of tactile all-odynia and thermal hyperalgesia rapidly,The expression of spinal neuronal apoptotic index in control group were significantly lower than those in the PAF group（P 〈0.01）.Conclusions Intrathecally administered PAF may induce development of tactile allodynia and thermal hyperalgesia in rats,and this process might be associ-ated with neuronal apoptosis in spinal cord.