Jiang Q, Sheldon R J, Porreca F
Department of Pharmacology, University of Arizona Health Sciences Center, Tucson 85724.
Life Sci. 1987 Nov 30;41(22):2455-61. doi: 10.1016/0024-3205(87)90671-0.
The gastrointestinal motor effects of centrally-given morphine and bombesin were compared in mice. Both compounds produced a dose-related decrease in the propulsion of a marker along the gut when given by the intracerebroventricular (i.c.v.) or intrathecal (i.th.) routes. Co-administration of the same compound by both routes was found to produce a marked increase in potency for morphine, but only a slight increase in potency for bombesin. Isobolographic analysis of the gut effects of these compounds revealed a multiplicative brain-spinal cord interaction for morphine, but an additive interaction for bombesin. These results are consistent with the interpretation that morphine can act at either the level of the brain or the spinal cord, activating independent pathways which ultimately converge to alter gut propulsion. In contrast, spinal bombesin requires communication to supraspinal sites in order for its gut effects to occur, suggesting activation of a common outflow pathway from the central nervous system.
在小鼠中比较了中枢给予吗啡和蛙皮素对胃肠运动的影响。当通过脑室内（i.c.v.）或鞘内（i.th.）途径给药时，这两种化合物都会使标记物沿肠道的推进出现剂量相关的减少。发现通过两种途径共同给予相同化合物时，吗啡的效力显著增加，但蛙皮素的效力仅略有增加。对这些化合物肠道效应的等效应线分析显示，吗啡存在脑-脊髓相乘相互作用，而蛙皮素存在相加相互作用。这些结果符合以下解释：吗啡可作用于脑或脊髓水平，激活独立的途径，这些途径最终汇聚以改变肠道推进。相比之下，脊髓给予蛙皮素需要与脊髓上部位进行通讯才能产生其肠道效应，这表明中枢神经系统激活了一条共同的传出途径。
