Bormann J, Clapham D E
Proc Natl Acad Sci U S A. 1985 Apr;82(7):2168-72. doi: 10.1073/pnas.82.7.2168.
We have studied membrane channels activated by gamma-aminobutyric acid (GABA) in adrenal medullary chromaffin cells by using patch-clamp techniques. These channels share many properties with GABA-receptor channels in the central nervous system. They are chloride-selective, blocked by the GABA antagonist bicuculline, and reversibly desensitized at high GABA concentrations. The dose-response curve has a slope of 2 in the Hill plot, indicating a bimolecular binding reaction of GABA to the receptor. Single-channel currents display multiple conductance states as do glycine-activated chloride channels in mouse spinal neurons. Gating properties of GABA-activated channels, as described by a sequential model for agonist-activated channels, are similar to gating properties in central neurons. GABA-induced currents are potentiated by diazepam, indicating that anxiolytic drugs like the benzodiazepines might be involved in the regulation of anxiety states in the peripheral nervous system.
我们运用膜片钳技术研究了肾上腺髓质嗜铬细胞中由γ-氨基丁酸（GABA）激活的膜通道。这些通道与中枢神经系统中的GABA受体通道具有许多共同特性。它们对氯离子具有选择性，被GABA拮抗剂荷包牡丹碱阻断，并在高浓度GABA下可逆脱敏。在希尔图中，剂量反应曲线的斜率为2，表明GABA与受体的双分子结合反应。单通道电流显示出多种电导状态，就像小鼠脊髓神经元中甘氨酸激活的氯离子通道一样。如激动剂激活通道的顺序模型所描述的，GABA激活通道的门控特性与中枢神经元中的门控特性相似。GABA诱导的电流被地西泮增强，这表明像苯二氮䓬类这样的抗焦虑药物可能参与外周神经系统焦虑状态的调节。
