摘要
目的 研究大鼠脊髓部位吗啡和可乐定镇痛机理及相互关系。方法 大鼠蛛网膜下腔埋管 ,以甩尾法测痛。结果 蛛网膜下腔注射 (i.t)吗啡和可乐定 ,其甩尾潜伏期随药物剂量的增加而延长 ;i.t吗啡和可乐定其镇痛作用呈协同 ;i.t酚妥拉明能减弱吗啡和可乐定的抗伤害性刺激作用 ;但纳洛酮仅抑制吗啡的抗伤害性刺激作用 ,对可乐定的镇痛作用无明显影响 ;i.t吗啡耐药大鼠对i.t可乐定的镇痛作用无明显影响。结论 脊髓部位阿片类药产生的抗伤害性刺激作用有赖于α2 受体的参与 ,但脊髓α2
Objective To study the analgesic mechanisms associated with intrathecal actions of morphine and clonidine in rats.Method Rats were implanted with chronic catheters constructed from PE 10 polyethylene tubing.The tip of each catheter rested at the rostral face of the lumber enlargement in the spinal subarachnoid space.The tail flick consisted of laying the rat's tail across a slit under which was a focused projection bulb.The response measure was the time between the light being switched on and the tail being briskly moved from the slit.Results After intrathecal injection of morphine and clonidine produced a dose dependent analgesia;small dose of intrathecal clonidine potentiated the analgesic efficiency of morphine;the intrathecal administration of phentolamine attenuated the antinociceptive effect both of clonidine and morphine,while naloxone attenuated only response of the morphine;in i.t morphine tolerant rats,intrathecal morphine reduced its original analgesic efficiency,whereas clonidine at the mean time retained its full analgesic potency without any change.Conclusions Apparently α 2 adrenergic receptor agonists mediated antinociceptive action independently without opioid receptor mechanism involved;in the spinal level of rat,α 2 receptor mechanism may play a different way as those opioids.
出处
《苏州医学院学报》
2000年第9期804-806,共3页
Acta Academiae Medicinae Suzhou
关键词
蛛网膜下腔注射
镇痛
吗啡
可乐定
intrathecal injection
analgesia
morphine
clonidine
