Girardot M N, Holloway F A
Pharmacol Biochem Behav. 1984 Apr;20(4):631-3. doi: 10.1016/0091-3057(84)90315-0.
Continuous cold water swim ( CCWS , 3.5 min, 2 degrees C) induces a non-opiate type of analgesia since 14 mg/kg of naltrexone or 20 mg/kg of naloxone only partially antagonize this stress-induced analgesia (SIA) and since there is no cross-tolerance between CCWS and morphine-analgesia. Intermittent cold water swim ( ICWS ) analgesia is significantly antagonized by naltrexone (14 mg/kg). These studies suggested that CCWS -analgesia is mediated by non-opioid systems, while ICWS -analgesia acts through a system that also mediates morphine analgesia. The hypothesis that ICWS -analgesia shares a common opioid pathway with morphine-analgesia, but not with CCWS -analgesia, was further tested by cross-tolerance studies in rats. The results showed a complete cross-tolerance to morphine analgesia in ICWS -tolerant animals,, but no cross-tolerance in animals. This suggests that morphine- and ICWS -analgesia partially share a common pathway, ICWS acting probably at levels "downstream" from the opiate-sensitive site, while CCWS induces analgesia by acting on a different system which is not mediated by opioids.
持续冷水游泳（CCWS，3.5分钟，2摄氏度）可诱导一种非阿片类镇痛，因为14毫克/千克的纳曲酮或20毫克/千克的纳洛酮只能部分拮抗这种应激诱导的镇痛（SIA），而且CCWS和吗啡镇痛之间不存在交叉耐受性。间歇性冷水游泳（ICWS）镇痛可被纳曲酮（14毫克/千克）显著拮抗。这些研究表明，CCWS镇痛是由非阿片类系统介导的，而ICWS镇痛是通过一个也介导吗啡镇痛的系统起作用的。ICWS镇痛与吗啡镇痛有共同的阿片类途径，但与CCWS镇痛没有共同途径这一假设，通过对大鼠的交叉耐受性研究得到了进一步验证。结果显示，对ICWS产生耐受性的动物对吗啡镇痛具有完全交叉耐受性，但在其他动物中没有交叉耐受性。这表明，吗啡和ICWS镇痛部分共享一条共同途径，ICWS可能作用于阿片敏感位点“下游”的水平，而CCWS通过作用于一个不由阿片类介导的不同系统诱导镇痛。
