Kayser V, Besson J M, Guilbaud G
Neuropeptides. 1984 Dec;5(1-3):49-52. doi: 10.1016/0143-4179(84)90024-6.
In arthritic rats, low doses of naloxone induced powerful analgesic effects (as gauged by the vocalization threshold elicited by pressure on the paw) which were marked for 3 and 6 micrograms/kg IV, whereas high doses (1000 and 3000 micrograms/kg IV) induced hyperalgesia. This bidirectional effect persisted in arthritic rats rendered tolerant to morphine, but whereas the analgesic effects were suppressed or reduced, the hyperalgesic effects induced by the higher doses were unchanged. These results suggest that the analgesic and hyperalgesic effects might be mediated by different systems.
在患有关节炎的大鼠中，低剂量的纳洛酮可产生强效镇痛作用（通过按压爪子所引发的发声阈值来衡量），静脉注射3微克/千克和6微克/千克时这种作用显著，而高剂量（静脉注射1000微克/千克和3000微克/千克）则会诱发痛觉过敏。这种双向效应在对吗啡产生耐受性的患有关节炎的大鼠中依然存在，但是尽管镇痛作用受到抑制或减弱，高剂量所诱发的痛觉过敏作用却未改变。这些结果表明，镇痛作用和痛觉过敏作用可能由不同的系统介导。
