Millan M J, Colpaert F C
Neurobiology Division, FONDAX-Groupe de Recherche SERVIER, Puteaux, France.
Neurosci Lett. 1990 May 18;113(1):50-5. doi: 10.1016/0304-3940(90)90493-s.
Rats were subcutaneously implanted with minipumps delivering naloxone (3.0 mg/kg/h) or distilled water. One day later, they were inoculated in the plantar surface of the right hind paw with Mycobacterium butyricum. Naloxone blocked the antinociceptive action of the mu-agonist, morphine, and the kappa-agonist, U69,593, and led to a sustained reduction in food and water intake. Thus, opioid receptors were effectively occupied. Rats receiving naloxone showed significantly less hindlimb swelling on days 2 and 3 post-implantation. On day 2 but not 5 post-implantation, the hyperalgesic response of the inoculated paw to noxious pressure was potentiated in rats receiving naloxone. At six days post-implantation, pumps were removed. Ten days after removal, the inflammation and hyperalgesia had spread to the contralateral hindlimb and to the forelimbs. The degree of this transfer was less pronounced in rats which had been receiving naloxone. These data suggest that opioids, via kappa-receptors, play a role in the control of nociception under inflammatory pain: however, this role may not be indispensable. Further, the processes governing the development and spread of inflammatory disease may be modulated by opioid mechanisms.
给大鼠皮下植入能输送纳洛酮（3.0毫克/千克/小时）或蒸馏水的微型泵。一天后，在大鼠右后爪的足底接种丁酸分枝杆菌。纳洛酮阻断了μ受体激动剂吗啡和κ受体激动剂U69,593的镇痛作用，并导致食物和水摄入量持续减少。因此，阿片受体被有效占据。接受纳洛酮的大鼠在植入后第2天和第3天的后肢肿胀明显减轻。在植入后第2天而非第5天，接受纳洛酮的大鼠接种爪对有害压力的痛觉过敏反应增强。植入后6天，取出微型泵。取出后10天，炎症和痛觉过敏已扩散到对侧后肢和前肢。在接受纳洛酮的大鼠中，这种转移的程度不太明显。这些数据表明，阿片类物质通过κ受体在炎性疼痛中对伤害性感受的控制中起作用：然而，这一作用可能并非不可或缺。此外，炎症性疾病的发生和扩散过程可能受阿片类机制调节。
