Lu F M, Xing B R, Chen Y Z
Department of Physiology, Second Military Medical University, Shanghai.
Sheng Li Xue Bao. 1994 Jun;46(3):238-43.
In guinea-pig celiac ganglion neurons, GABA induced a biphasic response, i.e. a depolarizing response associated with a resistance decrease followed by a hyperpolarizing response associated with a resistance increase. Such response persisted in low Ca2+ high Mg2+ medium. The GABA-induced biphasic response was mimicked by muscimol and inhibited by bicuculline methiodide (100 mumol/L) and picrotoxin (100-300 mumol/L). At doses producing almost equal depolarizing responses, muscimol was weaker in producing hyperpolarizing responses than GABA. Baclofen had no effect on membrane potentials of the ganglion cells. These results suggest that the depolarizing phase of the GABA-induced biphasic response is mediated by GABAA/Cl- ionophore receptor complex and the hyperpolarizing phase may be mediated by a novel type of GABA receptor possessing similar pharmacological properties as the classical GABAA receptor.
在豚鼠腹腔神经节神经元中，γ-氨基丁酸（GABA）诱发双相反应，即先是与电阻降低相关的去极化反应，随后是与电阻增加相关的超极化反应。这种反应在低钙高镁培养基中持续存在。GABA诱发的双相反应可被蝇蕈醇模拟，并被甲碘化荷包牡丹碱（100 μmol/L）和苦味毒（100 - 300 μmol/L）抑制。在产生几乎相等去极化反应的剂量下，蝇蕈醇产生超极化反应的能力比GABA弱。巴氯芬对神经节细胞膜电位无影响。这些结果表明，GABA诱发双相反应的去极化阶段由GABAA/Cl⁻离子载体受体复合物介导，而超极化阶段可能由一种新型GABA受体介导，该受体具有与经典GABAA受体相似的药理学特性。
