BARIUM PERMEABILITY OF NEURONAL NICOTINIC RECEPTOR-ALPHA-7 EXPRESSED IN XENOPUS-OOCYTES

被引：86

作者：

SANDS, SB ^{[1
]}

COSTA, ACS ^{[1
]}

PATRICK, JW ^{[1
]}

机构：

[1] BAYLOR COLL MED, DIV NEUROSCI, HOUSTON, TX 77030 USA

来源：

BIOPHYSICAL JOURNAL | 1993年 / 65卷 / 06期

基金：

美国国家卫生研究院;

关键词：

D O I：

10.1016/S0006-3495(93)81296-7

中图分类号：

Q6 [生物物理学];

学科分类号：

071011 ;

摘要：

The rat alpha7 neuronal nicotinic acetylcholine receptor was expressed and studied in Xenopus oocytes. The magnitude and reversal potential of instantaneous whole cell currents were examined in solutions containing varying concentrations of either calcium or barium, and in the presence or absence of the intracellular calcium chelator BAPTA. In external barium, application of nicotine elicits an inwardly rectifying response; in calcium the response is larger and has a linear IV relation. pretreatment of oocytes with BAPTA-AM could not prevent activation of calcium-dependent chloride channels in external Ringer containing calcium. Using an extended GHK equation, the permeability ratio P(Ba)/P(Na) of the alpha7 receptor was determined to be about 17. Our results suggest that alpha7 nicotinic receptors are highly permeable to divalent cations.

引用

页码：2614 / 2621

页数：8

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