Abe M, Matsuda M
Neurochem Res. 1983 May;8(5):563-73. doi: 10.1007/BF00964697.
[14C]Glutamic acid and [3H]GABA were injected into the lateral ventricle of mouse and then [14C]GABA and [3H]GABA in synaptosomes isolated from the animals were analysed. The [14C]GABA was interpreted to be newly synthesized GABA from [14C]glutamic acid while the [3H]GABA to be newly taken up GABA. We have obtained the following results: (1) when the animals were pretreated with aminooxyacetic acid and thus the GABA content in synaptosomes increased to about 2 times of the control level, only the [3H]GABA was enhanced to 3 times of the control level without any change of [14C]GABA, (2) the release of [14C]GABA from synaptosomes by high K+ depolarization was 1.5 times greater than that of [3H]GABA, (3) the releases of both [14C]GABA and [3H]GABA were increased in the presence of cold GABA, L-2,4-diaminobutyric acid or gamma-amino-beta-hydroxybutyric acid, but only slightly increased in the presence of beta-alanine. These results would suggest that newly synthesized GABA and newly taken up GABA localized individually in different pools, which might localize either in different nerve terminals or separately in the same nerve terminal.
将[¹⁴C]谷氨酸和[³H]γ-氨基丁酸注入小鼠侧脑室，然后分析从动物分离出的突触体中的[¹⁴C]γ-氨基丁酸和[³H]γ-氨基丁酸。[¹⁴C]γ-氨基丁酸被认为是由[¹⁴C]谷氨酸新合成的γ-氨基丁酸，而[³H]γ-氨基丁酸则是新摄取的γ-氨基丁酸。我们得到了以下结果：（1）当动物用氨氧基乙酸预处理，使突触体中的γ-氨基丁酸含量增加到对照水平的约2倍时，只有[³H]γ-氨基丁酸增加到对照水平的3倍，而[¹⁴C]γ-氨基丁酸没有任何变化；（2）高钾去极化使突触体释放的[¹⁴C]γ-氨基丁酸比[³H]γ-氨基丁酸多1.5倍；（3）在冷γ-氨基丁酸、L-2,4-二氨基丁酸或γ-氨基-β-羟基丁酸存在时，[¹⁴C]γ-氨基丁酸和[³H]γ-氨基丁酸的释放均增加，但在β-丙氨酸存在时仅略有增加。这些结果表明，新合成的γ-氨基丁酸和新摄取的γ-氨基丁酸分别定位于不同的池，这些池可能定位于不同的神经末梢，或者在同一神经末梢中分开定位。
