Kristal M B, Tarapacki J A, Barton D
Department of Psychology, State University of New York, Buffalo 14260.
Physiol Behav. 1990 Jan;47(1):79-81. doi: 10.1016/0031-9384(90)90044-5.
Ingestion of amniotic fluid or placenta by rats has been shown to enhance several types of opioid-mediated analgesia: that induced by morphine, footshock, vaginal/cervical stimulation, and late pregnancy. This enhancement has also been blocked by administration of opioid antagonists. The present study was designed to examine further the specificity of the enhancement effect for opioid-mediated analgesia by testing for enhancement following administration of aspirin, a nonopioid analgesic. The formalin test was used as the pain threshold assay. Amniotic fluid or beef bouillon was administered by orogastric tube to rats that were treated either with morphine sulfate or saline, or pretreated with naltrexone, then treated with aspirin or vehicle. Both morphine and aspirin treatments produced analgesia. Amniotic fluid significantly enhanced the analgesia produced by morphine, but did not enhance the analgesia produced by aspirin, further suggesting that the enhancing effect of amniotic fluid ingestion is specific for opioid-mediated analgesia, such as that existing at the start of parturition.
已证明，大鼠摄入羊水或胎盘可增强多种类型的阿片类药物介导的镇痛作用：由吗啡、电击足部、阴道/宫颈刺激以及妊娠晚期诱导的镇痛作用。这种增强作用也可被阿片类拮抗剂的给药所阻断。本研究旨在通过测试给予非阿片类镇痛药阿司匹林后的增强作用，进一步检验对阿片类药物介导的镇痛作用增强效果的特异性。福尔马林试验用作疼痛阈值测定法。通过灌胃管向用硫酸吗啡或生理盐水治疗的大鼠，或用纳曲酮预处理然后用阿司匹林或赋形剂治疗的大鼠给予羊水或牛肉汤。吗啡和阿司匹林治疗均产生了镇痛作用。羊水显著增强了吗啡产生的镇痛作用，但未增强阿司匹林产生的镇痛作用，这进一步表明摄入羊水的增强作用对阿片类药物介导的镇痛作用具有特异性，例如分娩开始时存在的那种镇痛作用。
