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激活视网膜水平细胞离子型谷氨酸受体抑制γ - 氨基丁酸转运体电流

姜晓东, 孙焱, 王绪龙, 龚海庆, 梁培基^*

上海交通大学生命科学技术学院，上海 200240

摘要

本工作在酶解分离的鲫鱼视网膜水平细胞上研究了AMPA受体对γ- 氨基丁酸(γ-aminobutyric acid, GABA)转运体电流的调节作用。由1 mmol/L GABA所诱导的GABA转运体电流被持续50 s 的AMPA (30 μmol/L 或 3 mmol/L)预灌流所抑制。在细胞内液中施加10 mmol/L BAPTA可以减弱AMPA对GABA转运体电流的抑制效应。施加3 mmol/L AMPA + 3 mmol/L NMDA所引起的抑制效应和单独施加3 mmol/L AMPA 或3 mmol/L NMDA所引起的抑制效应相仿。以上结果表明，和激活NMDA受体调节GABA 转运体的机制一样，激活视网膜水平细胞上的AMPA 受体可以通过胞内钙过程来抑制GABA 转运体电流。

关键词： GABA 转运体; AMPA 受体; NMDA 受体; 水平细胞; 视网膜

分类号：Q436

Suppression of γ-aminobutyric acid transporter current by activation of ionotropic glutamate receptors on retinal horizontal cells

JIANG Xiao-Dong, SUN Yan, WANG Xu-Long, GONG Hai-Qing, LIANG Pei-Ji^*

School of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200240, China

Abstract

In the present study, the modulatory effect of AMPA receptors on γ-aminobutyric acid (GABA) transporter current was investigated on enzymatically isolated horizontal cells of carp retina. The GABA transporter current elicited by 1 mmol/L GABA was decreased immediately after pre-application of AMPA (30 μmol/L or 3 mmol/L) for 50 s. Application of 10 mmol/L BAPTA in intracellular solution inhibited the suppression effect of AMPA on GABA transporter current. The suppression effect induced by coapplication of 3 mmol/L AMPA and 3 mmol/L NMDA was similar to that of 3 mmol/L AMPA or 3 mmol/L NMDA alone. These results suggest that the activation of AMPA receptors inhibits GABA transporter-mediated current by affecting intracellular Ca2+ processes in the retinal horizontal cells, which is identical with the modulatory effect of NMDA receptors on GABA transporters.

Key words: GABA transporter; AMPA receptor; NMDA receptor; horizontal cell; retina

收稿日期：2009-03-18　　录用日期：2009-05-05

通讯作者：梁培基　　E-mail: pjliang@sjtu.edu.cn

引用本文：

姜晓东, 孙焱, 王绪龙, 龚海庆, 梁培基. 激活视网膜水平细胞离子型谷氨酸受体抑制γ - 氨基丁酸转运体电流[J]. 生理学报 2009; 61 (4): 299-304.

JIANG Xiao-Dong, SUN Yan, WANG Xu-Long, GONG Hai-Qing, LIANG Pei-Ji. Suppression of γ-aminobutyric acid transporter current by activation of ionotropic glutamate receptors on retinal horizontal cells. Acta Physiol Sin 2009; 61 (4): 299-304 (in Chinese with English abstract).