Nicholls D G, Sihra T S
Nature. 1986;321(6072):772-3. doi: 10.1038/321772a0.
There is increasing evidence that L-glutamate is a major excitatory neurotransmitter in the central nervous system. Immunocytochemical studies indicate that glutamate within nerve terminals may be concentrated in vesicles and glutamate-accumulating vesicles have recently been isolated. Exocytotic release of glutamate from synaptosomes (isolated nerve terminals) has not been convincingly demonstrated, however, and remains highly controversial. In order to study the kinetics of release of endogenous L-glutamate from guinea pig cerebral cortical synaptosomes we have devised a continuous enzymatic assay. This has enabled us to identify a pool, equivalent to 15-20% of the total synaptosomal glutamate, which is capable of rapid Ca2+-dependent exocytotic release.
越来越多的证据表明，L-谷氨酸是中枢神经系统中的一种主要兴奋性神经递质。免疫细胞化学研究表明，神经末梢内的谷氨酸可能集中在囊泡中，并且最近已经分离出了积累谷氨酸的囊泡。然而，从突触体（分离的神经末梢）中通过胞吐作用释放谷氨酸尚未得到令人信服的证明，并且仍然存在很大争议。为了研究豚鼠大脑皮质突触体中内源性L-谷氨酸的释放动力学，我们设计了一种连续酶促测定法。这使我们能够鉴定出一个相当于突触体总谷氨酸15%-20%的池，该池能够快速进行依赖Ca2+的胞吐释放。
