Osorio I, Davidoff R A
Ann Neurol. 1979 Aug;6(2):111-6. doi: 10.1002/ana.410060206.
gamma-Hydroxybutyric acid (GHB), a pharmacologically active central nervous system constituent, has been postulated to function as a gamma-aminobutyric acid (GABA) agonist. This hypothesis was tested directly on GABAergic synapses in isolated, superfused frog spinal cord. Addition of GHB to the superfusate produced effects on primary afferent terminals that were distinctly different from the effects of GABA. Thus, although both compounds depressed dorsal root potentials, GHB hyperpolarized terminals while GABA depolarized the same structures. The GABA responses were antagonized by bicuculline and picrotoxin, but these alkaloids did not change GHB's actions. In addition, GHB altered neither high-affinity uptake by cord slices, nor potassium-evoked release of tritiated GABA from them. GHB did not directly release GABA from spinal slices preloaded with [3H]GABA. These observations suggest that the central nervous system actions of GHB are not dependent upon its ability to activate GABAergic synapses or to modify GABAergic mechanisms.
γ-羟基丁酸（GHB）是一种具有药理活性的中枢神经系统成分，据推测它作为γ-氨基丁酸（GABA）激动剂发挥作用。该假设在离体、灌流的青蛙脊髓中的GABA能突触上进行了直接测试。向灌流液中添加GHB对初级传入终末产生的作用与GABA的作用明显不同。因此，尽管这两种化合物都能抑制背根电位，但GHB使终末超极化，而GABA使相同结构去极化。GABA反应被荷包牡丹碱和印防己毒素拮抗，但这些生物碱并未改变GHB的作用。此外，GHB既不改变脊髓切片的高亲和力摄取，也不改变钾诱发的切片中氚标记GABA的释放。GHB不会直接从预先加载[3H]GABA的脊髓切片中释放GABA。这些观察结果表明，GHB在中枢神经系统的作用并不依赖于其激活GABA能突触或改变GABA能机制的能力。
