Weller A, Blass E M
Department of Psychology, Johns Hopkins University, Baltimore, Maryland 21218.
Am J Physiol. 1988 Dec;255(6 Pt 2):R901-7. doi: 10.1152/ajpregu.1988.255.6.R901.
In adult mammals, cholecystokinin (CCK)-opiate interactions are complex and task dependent. Specifically, CCK antagonizes opiate effects in some cases, yet acts similarly to opiate agonists in others. The present study used behavioral measures to determine how CCK interacts with opiates in neonatal rats. CCK, at doses of 1 microgram/kg and higher, markedly reduced isolation-induced distress vocalization in rat pups. Moreover, CCK selectively prevented naltrexone antagonism of opiate-mediated reduction in distress vocalization in 3- and 11-day-old rats. Yet CCK did not affect opiate-induced analgesia, as measured by the hot-plate paw-lift response. Thus CCK either did not interact with opiates or did so agonistically, with the same (low) dose range, and within subjects. These findings suggest independence of stress and pain systems in neonatal rats and demonstrate a functional interaction between CCK and opioid systems.
在成年哺乳动物中，胆囊收缩素（CCK）与阿片类物质的相互作用复杂且依赖于任务。具体而言，CCK在某些情况下会拮抗阿片类物质的作用，但在其他情况下其作用类似于阿片类激动剂。本研究采用行为学方法来确定CCK在新生大鼠中如何与阿片类物质相互作用。剂量为1微克/千克及以上的CCK显著减少了幼鼠隔离诱导的痛苦叫声。此外，CCK选择性地阻止了纳曲酮对3日龄和11日龄大鼠中阿片类物质介导的痛苦叫声减少的拮抗作用。然而，通过热板爪抬反应测量，CCK并未影响阿片类物质诱导的镇痛作用。因此，CCK要么不与阿片类物质相互作用，要么以相同的（低）剂量范围在个体内以激动方式相互作用。这些发现表明新生大鼠的应激系统和疼痛系统相互独立，并证明了CCK与阿片系统之间存在功能相互作用。
