Woolfolk D R, Holtzman S G
Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA.
Pharmacol Biochem Behav. 1995 Aug;51(4):699-703. doi: 10.1016/0091-3057(94)00440-t.
Restraint stress has been shown to increase the magnitude and duration of morphine-induced analgesia; however, this phenomenon has only been investigated using the Sprague-Dawley rat strain. The purpose of this study was to determine if other rat strains would also exhibit a potentiated analgesic response to morphine compared to their unrestrained controls. Dose-response and time course curves for the analgesic effect of morphine (1.0, 3.0, 5.6, 10 mg/kg) were generated in adult, male Wistar, Lewis, Fischer 344, Long-Evans Hooded, and Sprague-Dawley rats either unrestrained or restrained in Plexiglas cylinders, using the tail flick assay. Morphine produced dose-dependent increases in tail flick latencies, and this effect was potentiated by restraint stress in the Sprague-Dawley, Wistar, Lewis, and Fischer 344 strains, but not in the Long-Evans Hooded rats. Because Sprague-Dawley and Wistar rats displayed the most robust stress effect, the use of either of these rat strains is appropriate in studying the mechanisms of stress-induced potentiation of analgesia. The differences among rat strains demonstrated in this study may serve as a basis for correlation with opioid function.
应激束缚已被证明会增加吗啡诱导的镇痛效果的强度和持续时间；然而，这一现象仅在斯普拉格-道利大鼠品系中进行过研究。本研究的目的是确定与未受束缚的对照组相比，其他大鼠品系是否也会对吗啡表现出增强的镇痛反应。使用甩尾试验，在成年雄性Wistar大鼠、Lewis大鼠、Fischer 344大鼠、长-伊文斯有帽大鼠和斯普拉格-道利大鼠中，生成了吗啡（1.0、3.0、5.6、10 mg/kg）镇痛作用的剂量-反应曲线和时间进程曲线，这些大鼠要么未受束缚，要么被束缚在有机玻璃圆筒中。吗啡使甩尾潜伏期呈剂量依赖性增加，在斯普拉格-道利大鼠、Wistar大鼠、Lewis大鼠和Fischer 344大鼠品系中，这种作用因应激束缚而增强，但在长-伊文斯有帽大鼠中未增强。由于斯普拉格-道利大鼠和Wistar大鼠表现出最强的应激效应，在研究应激诱导的镇痛增强机制时，使用这两种大鼠品系中的任何一种都是合适的。本研究中大鼠品系之间的差异可作为与阿片类药物功能相关性研究的基础。
