AGONIST PHARMACOLOGY OF THE NEURONAL ALPHA-7 NICOTINIC RECEPTOR EXPRESSED IN XENOPUS-OOCYTES

被引:61
|
作者
AMAR, M [1 ]
THOMAS, P [1 ]
JOHNSON, C [1 ]
LUNT, GG [1 ]
WONNACOTT, S [1 ]
机构
[1] UNIV BATH,DEPT BIOCHEM,BATH BA2 7AY,AVON,ENGLAND
关键词
NEURONAL NICOTINIC RECEPTOR; NICOTINIC AGONIST; (+)-ANATOXIN-A; NICOTINE; ALPHA-BUNGAROTOXIN; XENOPUS OOCYTE;
D O I
10.1016/0014-5793(93)81005-K
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
The potencies and efficacies of seven agonists at chick alpha7 nicotinic receptors expressed in Xenopus oocytes were determined by whole cell recording. (+)-Anatoxin-a was the most potent agonist (EC50 = 0.58 muM) and acetylcholine was the least potent (EC50 = 320 muM). The rank order of agonist potencies was: (+)-anatoxin-a >> cytisine > (-)-nicotine > (+)-nicotine > DMPP > 1-acetyl-4-methylpiperazine methiodide > acetylcholine. DMPP evoked only very small currents: comparison of maximally effective agonist concentrations showed that DMPP was only one-fifth as efficacious as other agonists. Previously published IC50 values for rat brain [I-125]alpha-bungarotoxin sites show a similar agonist profile, and the identity of homo-oligomeric alpha7 receptors with native alpha-bungarotoxin-sensitive neuronal nicotinic receptors is discussed.
引用
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页码:284 / 288
页数:5
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