Wilcox R E, Severson J A, Woodward J J, Randall P K, Vaughn D M, Riffee W H
Department of Pharmacology and Toxicology, College of Pharmacy, University of Texas, Austin.
Brain Res. 1990 Sep 24;528(1):109-13. doi: 10.1016/0006-8993(90)90201-l.
Once daily subchronic pretreatments with the dopamine (DA) agonist apomorphine (APO) increase striatal DA synthesis and metabolism. Such changes imply that adaptations to APO do not dissipate completely within 24 h. In the present report we evaluated the effects of a single APO treatment 24 h prior to euthanasia on behavior and on striatal DA synthesis, metabolism, release and receptor binding. The single APO pretreatment reduced DA release from striatal synaptosomes. In contrast, striatal DA synthesis, metabolism, and the high-affinity binding of DA to the D2 receptor were unaltered 24 h after agonist pretreatment. At this time the stereotypic response to a subsequent APO challenge was enhanced. This adaptive pattern is different from that observed 60 min following an acute APO pretreatment, when high-affinity D2 binding is reduced. The pattern 24 h following a single APO pretreatment is also different from that observed following subchronic agonist dosing, when stereotypic behavior is enhanced, while basal DA synthesis and metabolism are increased.
每日一次用多巴胺（DA）激动剂阿扑吗啡（APO）进行亚慢性预处理可增加纹状体DA的合成与代谢。这些变化表明对APO的适应性在24小时内不会完全消失。在本报告中，我们评估了在安乐死24小时前单次给予APO对行为以及纹状体DA合成、代谢、释放和受体结合的影响。单次APO预处理减少了纹状体突触体中DA的释放。相比之下，激动剂预处理24小时后，纹状体DA的合成、代谢以及DA与D2受体的高亲和力结合未发生改变。此时，对随后APO激发的刻板反应增强。这种适应性模式不同于急性APO预处理60分钟后观察到的情况，那时高亲和力D2结合减少。单次APO预处理24小时后的模式也不同于亚慢性给予激动剂后的情况，那时刻板行为增强，而基础DA合成和代谢增加。
