【摘要】 大鼠经脊髓蛛网膜下腔(ith)埋置套管注射药物,用辐射热测定甩尾潜伏期作为痛阈。(1)单纯ith注射甲啡肽(MEK)50μg,亮啡肽(LEK)100μg,氨基肽酶抑制剂Bestatin50或100μg,对痛阈均无明显影响。(2)Bestatin可显著加强MEK的镇痛作用,但不能使LEK表现出镇痛效果。(3)Bestatin+MEK的镇痛作用可被纳洛酮所翻转。(4)ith D-丙~2-甲啡肽(DAME)使病阈显著升高,该作用并不能被Bestatin所加强。以上结果表明MEK在大鼠脊髓中具有显著镇痛作用,LEK则无效。更多还原

【Abstract】 After drugs were injected via preimplanted cannulae into the spinal subarachnoid space in rats, changes in the pain threshold were assessed by tail-flick test with radiant heat. The results are as follows:1. Methionine enkephalin (MEk) 50 μg, leucine enkephalin (LEK) 100 μg, aminopeptidase inhibitor bestatin 50 μg or 100 μg injected separately showed no significant effect on the pain threshold.2. Bestatin (50 μg) potentiated significantly the analgesic effect of MEK (50 μg), but had no effect on LEK (100 μg) which remained non-analgesic.3. The joined analgesic effect of bestatia and MEK could be antagonized by subcutaneous injection of naloxone (1 mg/kg).4. D-ala~2-met-enkepalin (DAME) 6 μg significantly increased the pain threshold in rats. This analgesic effect was not potentiated by bestatin (50 μg).The above results indicate that MEK, but not LEK, has a significant analgesic effect at the spinal level after the inhibition of its degrading enzyme.更多还原