Rowell P P, Winkler D L
J Neurochem. 1984 Dec;43(6):1593-8. doi: 10.1111/j.1471-4159.1984.tb06083.x.
The effects of nicotine and 1,1-dimethyl-4-phenylpiperazinium (DMPP) on the release of newly synthesized [3H]acetylcholine in mouse cerebral cortical synaptosomes were examined. Nicotine and DMPP produced increases in [3H]acetylcholine release, over the level of spontaneous release, of 24% and 30%, respectively, of a maximum depolarization-induced release produced by 50 mM potassium. The maximum effect was achieved at a concentration of 1 X 10(-4) M for both agents. The time course of release indicated a slow onset of action, reaching a maximum effect at 15 min of incubation. Both nicotine and DMPP also produced a slightly greater release of total tritium, measured in the absence of cholinesterase inhibition, than of [3H]acetylcholine. The release induced by nicotine was completely antagonized by hexamethonium and was largely (58%) calcium-dependent. Nicotine also produced an increase in [3H]choline accumulation into synaptosomes. These results indicate that the nicotinic agonists nicotine and DMPP can produce a moderate enhancement of acetylcholine release by a receptor-mediated action on cholinergic nerve terminals in the central nervous system.
研究了尼古丁和1,1 - 二甲基 - 4 - 苯基哌嗪鎓（DMPP）对小鼠大脑皮质突触体中新合成的[3H]乙酰胆碱释放的影响。尼古丁和DMPP使[3H]乙酰胆碱的释放量相对于自发释放水平分别增加了50 mM钾诱导的最大去极化诱导释放量的24%和30%。两种药物在浓度为1×10(-4) M时均达到最大效应。释放的时间进程表明作用起效缓慢，孵育15分钟时达到最大效应。在不存在胆碱酯酶抑制的情况下测量，尼古丁和DMPP还使总氚的释放量略高于[3H]乙酰胆碱的释放量。尼古丁诱导的释放完全被六甲铵拮抗，并且在很大程度上（58%）依赖于钙。尼古丁还使突触体中[3H]胆碱的积累增加。这些结果表明，烟碱激动剂尼古丁和DMPP可通过对中枢神经系统胆碱能神经末梢的受体介导作用适度增强乙酰胆碱的释放。
