Abstract：
This study determined whether consumption of a highly palatable liquid is a reliable measure of inflammatory pain and antinociception in male and female rats. After a 10-day acquisition period, the impact of intraplantar oil vs. complete Freund adjuvant (CFA) on consumption of vanilla-flavored Ensure was assessed, with a sipper tube height 12 or 19 cm above the floor. CFA significantly decreased Ensure consumption, which completely recovered within 4-7 days to levels in oil-treated controls; neither sex nor sipper tube height significantly influenced Ensure consumption. CFA also significantly suppressed Ensure consumption in rats not exposed to the 10-day acquisition period, but only in males. To test the predictive validity of Ensure consumption as a measure of pain, separate rats were pretreated with a vehicle, an opioid, a nonsteroidal anti-inflammatory drug, or a cannabinoid the day after CFA treatment. Morphine and ibuprofen significantly attenuated CFA-suppressed drinking in at least one sex, and tetrahydrocannabinol did not. Neither ibuprofen nor tetrahydrocannabinol significantly altered drinking in oil-injected, \'pain-free\' controls, but morphine increased drinking. These results demonstrate that CFA decreases consumption of a highly palatable liquid regardless of previous exposure (training) to the consumption procedure, but only in males. Although standard analgesics attenuate CFA-suppressed drinking, nonspecific hyperphagic effects can confound the interpretation of results. Thus, consumption of a highly palatable liquid is not an optimal measure for candidate analgesic screening.
摘要：
这项研究确定了食用可口的液体是否是雄性和雌性大鼠炎性疼痛和抗伤害感受的可靠指标。经过10天的收购期，足底内油的影响与对食用香草味的完全弗氏佐剂(CFA)进行了评估，与吸管高度12或19厘米以上的地板。CFA大幅下降，确保消费，在4-7天内完全恢复到油处理对照组的水平；性别和吸管高度都不会显着影响确保消费。CFA还显着抑制了确保未暴露于10天获取期的大鼠的消耗，但只有男性。为了测试确保消费作为疼痛衡量标准的预测有效性，单独的大鼠用载体预处理，阿片类药物，一种非甾体抗炎药,或CFA治疗后第二天的大麻素。吗啡和布洛芬在至少一种性别中显着减弱了CFA抑制的饮酒，四氢大麻酚没有。布洛芬和四氢大麻酚都不会显着改变注油的饮酒量，\'无痛\'控件，但是吗啡增加了饮酒量.这些结果表明，无论以前是否接触（训练）食用程序，CFA都可以减少高度可口的液体的消耗。但只有男性。尽管标准镇痛药可减弱CFA抑制的饮酒，非特异性超常效应会混淆结果的解释。因此，高度可口的液体的消耗不是候选镇痛筛选的最佳措施。
