可乐定对大鼠脊髓背角伤害性神经元诱发放电的影响

The effects of clonidine on noxiously evoked activity of spinal dorsal horn neurons in rats

目的：以大鼠脊髓背角伤害性神经元的伤害刺激诱发放电作为痛指标，观察脊髓表面应用可乐定对该指标的影响。方法：选用ＳＤ大鼠３１只，随机分为５组：（１）生理盐水对照（鼠数＝５）；（２）可乐定５μｇ组（鼠数＝５）；（３）可乐定１０μｇ组（鼠数＝８）；（４）可乐定２０μｇ组（鼠数＝６）；（５）可乐定３０μｇ（鼠数＝７）。用药方式为脊髓表面滴注。结果：各剂量组可乐定均对脊髓背角伤害性神经元的伤害刺激诱发放电有抑制作用，剂量低于２０μｇ时，药效随剂量增大而增强，剂量增至３０μｇ时，药效无显著增强。结论：可乐定对大鼠脊髓背角伤害性神经元诱发放电有抑制作用，且有明显剂量－效应关系。

Objective:The experiment was conducted to evaluate the effects of clonidine on noxiously evoked activity of spinal dorsal horn neurons by a sensitive neurophysiologic assay Methods:Thirty one SD rats were randomly divided into five groups:(1)control group (n=5) (2)clonidine 5μg(n=5) (3)clonidine 10μg(n=8) (4)clonidine 20μg(n=6) (5)clonidine 30μg(n=7) All drugs were topically administered to the spinal in each group The unit discharge of spinal dorsal horn neurons was recorded at L2 L3 level in immobilized rats and the responses of dorsal horn neurons to nociceptive stimmuli before and after using clonidine were observed Results:The unit discharge frequency of the nociceptive response of dorsal horn neurons was significantly decresed after using different dosage of clonidine Conclusion:Topically spinal administration of clonidine has a dose related antinociceptive effect