Ugarte Yvette V, Rau Kristi S, Riddle Evan L, Hanson Glen R, Fleckenstein Annette E
Department of Pharmacology and Toxicology, University of Utah, 30 South 2000 East, Room 201, Salt Lake City, UT 84112, USA.
Eur J Pharmacol. 2003 Jul 11;472(3):165-71. doi: 10.1016/s0014-2999(03)01911-3.
Multiple high-dose administrations of the dopamine-releasing agent, methamphetamine, rapidly and persistently decrease vesicular dopamine uptake in purified vesicles prepared from striata of treated rats. Because important differences in the neurotoxic effects of stimulants have been documented in rats and mice, the purpose of this study was to determine if methamphetamine-induced effects in rats occur in mice and to elucidate mechanisms underlying these effects. Results reveal methamphetamine treatment rapidly decreased mouse striatal vesicular dopamine uptake; a phenomenon associated with a subcellular redistribution of vesicular monoamine transporter-2 (VMAT-2) immunoreactivity. Both methamphetamine-induced hyperthermia and dopamine D2 receptor activation contributed to the stimulant-induced deficits in vesicular dopamine uptake. Unlike methamphetamine, the dopamine reuptake inhibitors, methylphenidate and cocaine, rapidly increased vesicular dopamine uptake. The implications of these phenomena are discussed.
多次大剂量给予多巴胺释放剂甲基苯丙胺,可使从经处理大鼠纹状体制备的纯化囊泡中囊泡多巴胺摄取迅速且持续减少。由于已证明兴奋剂在大鼠和小鼠中的神经毒性作用存在重要差异,本研究的目的是确定甲基苯丙胺在大鼠中诱导的效应是否在小鼠中出现,并阐明这些效应的潜在机制。结果显示,甲基苯丙胺处理迅速降低了小鼠纹状体囊泡多巴胺摄取;这一现象与囊泡单胺转运体2(VMAT-2)免疫反应性的亚细胞重新分布有关。甲基苯丙胺诱导的体温过高和多巴胺D2受体激活均导致了兴奋剂诱导的囊泡多巴胺摄取缺陷。与甲基苯丙胺不同,多巴胺再摄取抑制剂哌甲酯和可卡因可迅速增加囊泡多巴胺摄取。文中讨论了这些现象的意义。