摘要
目的观察大鼠脊髓蛛网膜下腔注射多巴胺(DA)对痛觉的调制作用。方法实验用Wistar大鼠40只,钾离子透入法引起大鼠甩尾的电流强度(mA)为痛反应指标,测定动物痛阈,以电刺激坐骨神经作为伤害性刺激,玻璃微电极引导尾核痛兴奋神经元(PEN)的放电。结果脊髓蛛网膜下腔注射DA后,可使大鼠痛阈明显升高,尾核PEN诱发放电频率减少,潜伏期延长。DA作用高峰出现在注药后4min,与注药前比较痛阈增加(73.15±3.78)%(P<0.01),PEN放电频率抑制率为(81.98±9.03)%(P<0.01)。上述效应可被腹腔内注射DA受体阻断剂氟哌啶醇所阻断。结论在脊髓水平注射DA具有明显的镇痛作用,其机制可能是DA作用于脊髓神经元的DA受体,抑制了伤害信息向脑的传递。
Objective To study the role of dopamine（DA） injected into subarachnoid space in pain modulation. Methods The potassium ionophoresis induced tail-flick was used to measure the pain theshold,the electrocal stimulation of sciatic nerve was used as noxious stimulus, the electrical activity of pain excitation neuron （ PEN ）of caudate nucleus were recorded by glass microelectrode in 40 Wistar rats. Results DA administration into subarachnoid space increased the pain theshold, decreased the discharge frequency and increased the latency of PEN, the effect of DA appeared after injected about 4 min, the pain threshold increased （73.15 ± 3.78） % （ P 〈 0.01 ）, compared with non-treatment, and the inhibition ratio of discharge frequencey of PEN was（81.98 ± 9.03） % （ P 〈 0.01 ） . These effects could be blocked by DA antagonist haloperidol. Conclusion These results indicated that DA inhibits pain at the spinal cord level. The mechanism maybe DA can influence the neuronic DA receptor to inhabit the injure information transmit to the brain.
出处
《潍坊医学院学报》
2007年第2期114-116,I0002,共4页
Acta Academiae Medicinae Weifang
关键词
蛛网膜下腔
多巴胺
痛觉调制
Subarachnoid space
Dopamine
Pain modulation
