Lang I M, Strahlendorf J C, Strahlendorf H K, Barnes C D
Prog Clin Biol Res. 1981;68:197-207.
Opioid antagonists have been reported to reduce water and food intake. In the experiments, ingestive behavior was sometimes induced using stressful stimuli. These experiments were conducted to determine the effects of chronic administration of an opioid antagonist on appetitive behaviors of minimally stressed rats. Twelve 4-week old rats were randomly separated into two equal-sized groups, anesthetized with ether, and implanted subcutaneously with poly(epsilon-caprolactone) capsules. One group received naltrexone in the capsules, the other group received vehicle. These capsules released the drug at a rate of approximately 250 microgram/day for over 8 weeks. Gross metabolic behavior (food intake, water intake, urine output, fecal output, and body weight) was monitored for 8 weeks. At three times during the 8 weeks, food deprivation (24 hr)-induced feeding was tested over a period of 60 min. At the end of the eighth week, the animals were subjected to an analgesic test in order to confirm the efficacy of the naltrexone dose. No differences in food intake, body weight, fecal output, or deprivation-induced feeding were observed between the control and naltrexone groups. Water intake and fluid output of the naltrexone group were significantly reduced compared to the control group. These results suggest that endogenous opioids may mediate mechanisms of tonic drinking behavior and cannot be explained as representing effects on stress-induced ingestion.
据报道，阿片类拮抗剂可减少水和食物的摄入量。在实验中，有时会使用应激刺激来诱导摄食行为。进行这些实验是为了确定长期给予阿片类拮抗剂对轻度应激大鼠的食欲行为的影响。将12只4周龄的大鼠随机分成两组，每组大小相等，用乙醚麻醉后，皮下植入聚（ε-己内酯）胶囊。一组在胶囊中接受纳曲酮，另一组接受赋形剂。这些胶囊以约250微克/天的速率释放药物，持续8周以上。对总体代谢行为（食物摄入量、水摄入量、尿量、粪便量和体重）进行了8周的监测。在8周内的三个时间点，对禁食（24小时）诱导的进食进行了60分钟的测试。在第八周结束时，对动物进行镇痛测试，以确认纳曲酮剂量的有效性。在对照组和纳曲酮组之间，未观察到食物摄入量、体重、粪便量或禁食诱导的进食有差异。与对照组相比，纳曲酮组的水摄入量和液体排出量显著减少。这些结果表明，内源性阿片类物质可能介导了紧张性饮水行为的机制，而不能解释为对应激诱导摄食的影响。
