Reuter H
Department of Pharmacology, University of Bern, Switzerland.
Neuron. 1995 Apr;14(4):773-9. doi: 10.1016/0896-6273(95)90221-x.
The effect of various Ca(2+)-channel blockers on exocytosis has been studied at the level of single presynaptic terminals in rat hippocampal cell cultures. The fluorescence change of the styryl dye FM 1-43 has been used as a measure of exocytosis during electrical stimulation. omega-Conotoxin GVIA (2-10 microM) completely inhibited exocytosis in approximately 45% of the boutons in the field of view, while in approximately 55% exocytosis was inhibited incompletely (by 38%). This heterogeneity in response of presynaptic boutons was not seen with isradipine (5 microM) or omega-agatoxin IVA (80 nM), which inhibited exocytosis by 23% and 17%, respectively. However, it was observed with a combination of all three blockers. Pre- and postsynaptic events could be separated in single synapses by measuring FM1-43 release and NMDA-induced changes in the intracellular Ca2+ concentration independently.
在大鼠海马细胞培养物的单个突触前终末水平上，研究了各种钙通道阻滞剂对胞吐作用的影响。在电刺激期间，将苯乙烯基染料FM 1-43的荧光变化用作胞吐作用的指标。ω-芋螺毒素GVIA（2-10微摩尔）在视野中约45%的突触小体中完全抑制了胞吐作用，而在约55%的突触小体中胞吐作用被不完全抑制（抑制38%）。用异搏定（5微摩尔）或ω-阿加毒素IVA（80纳摩尔）时未观察到突触前终末反应的这种异质性，它们分别抑制胞吐作用23%和17%。然而，在三种阻滞剂联合使用时观察到了这种异质性。通过分别测量FM1-43释放和NMDA诱导的细胞内钙离子浓度变化，可以在单个突触中分离突触前和突触后事件。
