Agonist pharmacology of the neuronal α7 nicotinic receptor expressed in Xenopus oocytes
Authors:
- C. JohnsonC. Johnson
- S. WonnacottSWS. Wonnacott
- 2 August 1993
- journal article
- Published by Wiley in FEBS Letters
- Vol. 327 (3) , 284-288
Abstract
The potencies and efficacies of seven agonists at chick α7 nicotinic receptors expressed in Xenopus oocytes were determined by whole cell recording. (+)‐Anatoxin‐a was the most potent agonist (EC50 = 0.58 μM) and acetylcholine was the least potent (EC50 = 320 μM). 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 [125I]α‐bungarotoxin sites show a similar agonist profile, and the identity of homo‐oligomeric α7 receptors with native α‐bungarotoxin‐sensitive neuronal nicotinic receptors is discussed.Keywords
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