可乐定对脊髓P物质释放的影响

Effects of clonidine on release of substance P from rat spinal cord

目的:研究可乐定对大鼠脊髓P物质释放的影响,旨在探讨可乐定镇痛作用的脊髓途径。方法:20只SD大白鼠随机分为可乐定组和对照组,各10只。可乐定组大鼠腹腔注射可乐定40μg,对照组注射等量生理盐水。取脊髓腰段(L_(2～3))多聚甲醛固定的冰冻切片。P物质免疫组化显示用过氧化物酶-抗过氧化物酶法(PAP法)。结果:可乐定用药组的大鼠脊髓后角中外区及背外侧核区光密度OD值较对照组显著增高(P<0.05),P物质免疫反应产物显著增多,以Ⅰ～Ⅲ层最为明显。结论:可乐定通过抑制脊髓后角及背外侧核区P物质释放,从而抑制伤害性刺激的一级传入。

To study effects of clonidine on release of substance P from rat spinal cord for analysing the spinal sites of its pain relief, Method: Twenty rats were randomly divided into two groups: clonidine group and control group, clonidine 40μg or normal saline was injected intraperitoneally. Immunohistochemica] PAP technique was used to measure substance P in slices of rat spinal cord. Result: The optical density(OD) of immunoreaction of substance P in medial-lateral part of spinal dorsal horn and spinal Lissauer's tract was increased significantly in clonidine group com pared with that of control group (P<0.05). Conclusion: Clonidine inhibites spinal nociceptive sensory afferent through inhibiting the release of substance P from rat spinal dorsal horn and spinal Lisauer's tract.