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豚鼠腹腔神经节细胞γ-氨基丁酸双相反应的药理学特性

陆芳民, 邢宝仁, 陈宜张

第二军医大学生理学教研室. 上海(200433)

摘要

在豚鼠腹腔神经节细胞, γ-氨基丁酸(GABA)可诱发“去极化-超极化”的双相反应, 去极化伴膜电阻减小, 超极化伴膜电阻增大, 该反应在低钙高镁液中仍然存在。蝇蕈醇可模拟GABA双相反应, 但在诱发相同强度的去极化反应时, 蝇蕈醇产生的超极化弱于GABA。荷包牡丹碱(100μmol/L)和印防己毒素(100-300μmol/L)能可逆地抑制GABA诱发的双相反应。Baclofen对神经节细胞 的膜电位无明显影响。结果提示, GABA双相反应的去极化相由GABA_(A)/Cl~(-)通道受体复合物介导,而超极化相很可能由不同于经典的GABA_(A)受体, 但其药理学行为又由与之十分相近的另一种GABA受体介导。

关键词： γ－氨基丁酸; 双相反应; 膜电阻; γ－氨基丁酸－苯二氮受体; 交感神经节

The Pharmacology of the GABA-induced biphasic response in guinea-pig celiac ganglion neurons in vitro

Lu Fangmin, Xing Baoren, Chen Yizhang

Department of Physiology, Second Military Medical University. Shanghai

Abstract

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 Ca~(2+) high Mg~(2+) medium. The GABA-induced biphasic response was mimicked by muscimol and inhibited by bicuculline methiodide (100#mu#mol/L)and picrotoxin(100—300#mu#mol/L). At doses producing almost equal depolarizing responses, muscimol was weaker in producing hyperpolarizing responsis than GABA. Baclofen had no effect on membrane potentials of the ganglion cells. These results suggest that hte depolarizing phase of the GABA-induced biphasic response is mediated by GABA_(A)/Cl~(-) ionophore receptor complex and the hyperpolarzing phase may be mediated by a novel type of GABA receptor possessing similar pharmacological properties as the classified GABA receptor.

Key words: GABA;Biphasic response;Membrane resistallce;GABA-benzodiatepine receptors; Sympathetic ganglia

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引用本文：

陆芳民, 邢宝仁, 陈宜张. 豚鼠腹腔神经节细胞γ-氨基丁酸双相反应的药理学特性[J]. 生理学报 1994; 46 (3): .

Lu Fangmin, Xing Baoren, Chen Yizhang. The Pharmacology of the GABA-induced biphasic response in guinea-pig celiac ganglion neurons in vitro. Acta Physiol Sin 1994; 46 (3): (in Chinese with English abstract).