Baba A, Okumura S, Mizuo H, Iwata H
J Neurochem. 1983 Jan;40(1):280-4. doi: 10.1111/j.1471-4159.1983.tb12683.x.
Effects of diazepam and γ-aminobutyric acid-related compounds on the release of [¹⁴C]cysteine sulfinate and [³H]glutamate from preloaded hippocampal slices of rat brain were examined by a superfusion method. Diazepam markedly inhibited the release of cysteine sulfinate and glutamate evoked either by high K⁺ or veratridine without affecting that of other neurotransmitter candidates, e.g., γ-aminobutyric acid, acetylcholine, noradrenaline, and dopamine; IC₅₀ values for the release of cysteine sulfinate and glutamate were about 20 and 7 μM, respectively. γ-Aminobutyric acid (1 to 10 μM) and muscimol (100 μM) significantly reduced high K⁺-stimulated release of glutamate. Bicuculline, which had no effect on the release at a concentration of 50 μM by itself, antagonized the inhibitory effects of diazepam and γ-aminobutyric acid on glutamate release. Similar results were obtained with the release of cysteine sulfinate except that a high concentration (100 μM) of γ-aminobutyric acid was required for the inhibition. These results indicate the modulation by γ-aminobutyric acid innervation of the release of excitatory amino acids in rat hippocampal formation, and also suggest that some of the pharmacological effects of diazepam may be a consequence of inhibition of excitatory amino acid transmission.
采用灌流法研究了地西泮和γ-氨基丁酸相关化合物对预先加载的大鼠脑海马切片中[¹⁴C]半胱氨酸亚磺酸盐和[³H]谷氨酸释放的影响。地西泮显著抑制高钾或藜芦碱诱发的半胱氨酸亚磺酸盐和谷氨酸的释放，而不影响其他神经递质候选物如γ-氨基丁酸、乙酰胆碱、去甲肾上腺素和多巴胺的释放；半胱氨酸亚磺酸盐和谷氨酸释放的IC₅₀值分别约为20和7μM。γ-氨基丁酸（1至10μM）和蝇蕈醇（100μM）显著降低高钾刺激的谷氨酸释放。荷包牡丹碱本身在50μM浓度时对释放无影响，但拮抗地西泮和γ-氨基丁酸对谷氨酸释放的抑制作用。半胱氨酸亚磺酸盐释放也得到了类似结果，只是抑制需要高浓度（100μM）的γ-氨基丁酸。这些结果表明γ-氨基丁酸神经支配对大鼠海马结构中兴奋性氨基酸释放的调节作用，也提示地西泮的某些药理作用可能是抑制兴奋性氨基酸传递的结果。
