大鼠脑室或脊髓蛛网膜下腔注射八肽胆囊收缩素抗血清翻转吗啡耐受

连续6天给大鼠皮下注射递增剂量的盐酸吗啡(5～30mg/kg),则吗啡镇痛效果逐渐减弱,产生耐受。给吗啡耐受的大鼠侧脑室(icv)注射八肽胆囊收缩素(CCK-8)抗血清2μl,可使吗啡耐受作用被翻转50％(P<0.001)。给吗啡耐受的动物以电针刺激,表明电针与吗啡镇痛两者之间有交叉耐受。icv注射CCK-8抗血清可使电针交叉耐受翻转50％以上(P<0.001)。脊髓蛛网膜下腔(ith)注射CCK-8抗血清也可产生类似的作用,但不如icv注射的明显。单独icv或ith注射CCK-8抗血清对痛阈无显著影响。以上结果表明中枢神经系统CNS)中CCK-8可能参与吗啡耐受的形成机理。

Reversal Effect of Morphine Tolerance by Octa-peptide Chole-cystokinin Antiserum Injected Intraventricularly or Intratheacally.

When morphine of progressively increasing dosages( 5-30mg/kg) was given subcutaneously for 6 days to rats, tolerance of morphine in its analgesic effect occured in the rats.Then, upon injection of 2 μl of octa-peptide cholecystokinin ( CCK- 8 ) antiserum into the lateral ventricles(icv) of the rats, a reversal of morphine tolerance to about 50%(P<0.001) was observed .Electroacupuncture ( EA ) given to animals with morphine tolerance also showed an abatement of its analgesic effect, indicating a cross tolerance between EA and morphine. By injecting CCK-8 antiserum icv,EA cross tolerance was reversed by more than 50%(P<0.001), and a similar though less pro-nouced effect was produced by injecting CCK- 8 antiserum into the arachnoid space in the spinal column (ith). No significant effect on the pain threshold of the animals was observed when CCK-8 antiserum alone was injected icv or ith. this suggests that CCK-8 in the central nerve system may be involved in the mechanism of morphine tolerance.