Shingu K, Osawa M, Omatsu Y, Komatsu T, Urabe N, Mori K
Acta Anaesthesiol Scand. 1981 Dec;25(6):526-32. doi: 10.1111/j.1399-6576.1981.tb01699.x.
The effects of several anaesthetics on spinal cord nociceptive neural mechanisms and their interactions with the opiate antagonist, naloxone, were studied in acute, spinal cord transected cats. Intra-arterial injection of bradykinin was used as the noxious test stimulus. Spontaneous activity and the neural response induced by bradykinin were recorded by the multi-unit activity technique in the lateral funiculus of the spinal cord. Naloxone, 0.1 or 2.0 mg/kg i.v. had little effect on the bradykinin-induced response, but enhanced the spontaneous firing of the lateral funiculus significantly. Fentanyl, 30 micrograms/kg i.v., depressed both the bradykinin-induced response and spontaneous firing. These effects of fentanyl were antagonized completely by naloxone, 0.1 mg/kg i.v. Nitrous oxide, thiamylal, halothane and ether depressed the bradykinin-induced response considerably, but it was not antagonized by naloxone, 0.1-2.0 mg/kg i.v. Enflurane had little effect on the bradykinin-induced response. The effects of these anesthetics on spontaneous firing were divergent: nitrous oxide enhanced it while other drugs depressed it, to various degrees. All these data suggest that the neural and/or neurochemical mechanisms of anesthetic-induced analgesia differ from mechanisms related to opioids.
在急性脊髓横断猫中，研究了几种麻醉剂对脊髓伤害性神经机制的影响及其与阿片类拮抗剂纳洛酮的相互作用。动脉内注射缓激肽用作有害测试刺激。通过多单位活动技术记录脊髓外侧索的自发活动和缓激肽诱导的神经反应。静脉注射0.1或2.0mg/kg的纳洛酮对缓激肽诱导的反应影响不大，但显著增强了外侧索的自发放电。静脉注射30μg/kg的芬太尼可抑制缓激肽诱导的反应和自发放电。静脉注射0.1mg/kg的纳洛酮可完全拮抗芬太尼的这些作用。氧化亚氮、硫喷妥钠、氟烷和乙醚可显著抑制缓激肽诱导的反应，但静脉注射0.1 - 2.0mg/kg的纳洛酮不能拮抗。恩氟烷对缓激肽诱导的反应影响不大。这些麻醉剂对自发放电的影响各不相同：氧化亚氮增强自发放电，而其他药物则不同程度地抑制自发放电。所有这些数据表明，麻醉诱导镇痛的神经和/或神经化学机制与阿片类药物相关机制不同。
