大鼠脑室注射强啡肽A(1～13)在冷水甩尾测痛中的镇痛及抗吗啡镇痛作用

ANALGESIC EFFECT OF DYNORPHIN A(1～13) AND ITS ANTAGONISTIC EFFECT ON MORPHINE ANALGESIA IN RAT BRAIN IN THE COLD WATER TAIL FLICK TEST ASSAY

建立大鼠冷水甩尾模型，观察脑室注射（ｉ．ｃ．ｖ．）强啡肽Ａ（１～１３）的镇痛作用及其对吗啡镇痛作用的影响。用冷水甩尾测痛观察皮下注射（ｓ．ｃ．）吗啡镇痛作用的时效和量效曲线以验证该测痛模型的可行性；强啡肽Ａ（１～１３）经侧脑室注射给药。冷水甩尾测痛模型稳定性好，灵敏度和准确度高；用冷水甩尾测痛时ｉ．ｃ．ｖ．强啡肽Ａ（１～１３）有明显的镇痛作用，并可剂量依赖地对抗ｓ．ｃ．吗啡的镇痛作用。冷水甩尾测痛能有效检测ｓ．ｃ．吗啡和ｉ．ｃ．ｖ．强啡肽的镇痛作用；大鼠ｉ．ｃ．ｖ．强啡肽Ａ（１～１３）可对抗ｓ．ｃ．吗啡的镇痛作用。

To construct the cold water tail flick test assay (CWT) and observe whether i.c.v. dynorphin A(1～13) in rats has analgesic effect itself and whether it can affect morphine induced analgesia.The feasibility of the CWT was demonstrated by the time effect course and the dose effect curve of analgesia induced by s.c. morphine,the effect of i.c.v. dynorphin A(1～13) and its action on s.c. morphine were then observed.The CWT showed a clear stability,high sensitivity and high accuracy in the assessment of nociception;i.c.v. injection of dynorphin A(1～13) demonstrated dose depended analgesic effect,yet antagonized the analgesia induced by s.c. morphine in the CWT.The CWT effectively detected the antinociception induced by s.c. morphine and i.c.v. dynorphin;i.c.v. dynorphin A(1～13) antagonized s.c. morphine induced analgesia in rats as assessed by CWT.