EXPRESSION OF MAMMALIAN GAMMA-AMINOBUTYRIC-ACID RECEPTORS WITH DISTINCT PHARMACOLOGY IN XENOPUS OOCYTES
EXPRESSION OF MAMMALIAN GAMMA-AMINOBUTYRIC-ACID RECEPTORS WITH DISTINCT PHARMACOLOGY IN XENOPUS OOCYTES
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DOI：
10.1073/pnas.88.10.4318
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发表时间：
1991-05-01
影响因子：
11.1
通讯作者：
MILEDI, R
中科院分区：
文献类型：
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作者：
POLENZANI, L;WOODWARD, RM;MILEDI, R
γ -氨基丁酸（GABA）是哺乳动物大脑中主要的抑制性神经递质，已知与GABA(A)和GABA(B)两类GABA受体相互作用。利用爪蟾卵母细胞，我们比较了从哺乳动物大脑和视网膜分离的poly(A)+ RNA表达的GABA受体的电学和药理学特性。来自大脑皮层的RNA表达GABA反应，具有GABA(A)受体介导的电流特征。相比之下，来自视网膜的RNA表达由GABA(A)受体介导的反应，此外，GABA反应对GABA(A)拮抗剂双库兰和GABA(B)激动剂巴氯芬不敏感，并且没有巴比妥酸盐或苯二氮卓类药物的调节。双球茎碱/巴氯芬不敏感的GABA反应是一种Cl-电流，被微毒素阻断，但几乎没有脱敏或向外整流。我们的研究结果表明，哺乳动物视网膜含有编码GABA受体的rna，具有不同的药理作用。
Gamma-aminobutyric acid (GABA), the major inhibitory neurotransmitter in mammalian brain, is known to interact with two classes of GABA receptors denoted GABA(A) and GABA(B). Using Xenopus oocytes, we compared the electrical and pharmacological properties of GABA receptors expressed by poly(A)+ RNA isolated from mammalian brain and retina. RNA from cerebral cortex expressed GABA responses with features characteristic of currents mediated by GABA(A) receptors. In contrast, RNA from retina expressed responses mediated by GABA(A) receptors and, in addition, GABA responses that were insensitive to the GABA(A) antagonist bicuculline and the GABA(B) agonist baclofen and showed no modulation by barbiturates or benzodiazepines. The bicuculline/baclofen-insensitive GABA response was a Cl- current that was blocked by picrotoxin but showed little desensitization or outward rectification. Our results suggest that mammalian retina contains RNAs encoding GABA receptors with distinct pharmacology.