PT  - JOURNAL ARTICLE
AU  - Rothlin, Carla V.
AU  - Katz, Eleonora
AU  - Verbitsky, Miguel
AU  - Elgoyhen, A. Belén
TI  - The α9 Nicotinic Acetylcholine Receptor Shares Pharmacological Properties with Type A γ-Aminobutyric Acid, Glycine, and Type 3 Serotonin Receptors
AID  - 10.1124/mol.55.2.248
DP  - 1999 Feb 01
TA  - Molecular Pharmacology
PG  - 248--254
VI  - 55
IP  - 2
4099  - http://molpharm.aspetjournals.org/content/55/2/248.short
4100  - http://molpharm.aspetjournals.org/content/55/2/248.full
SO  - Mol Pharmacol1999 Feb 01; 55
AB  - In the present study, we provide evidence that the α9 nicotinic acetylcholine receptor (nAChR) shares pharmacological properties with members of the Cys-loop family of receptors. Thus, the type A γ-aminobutyric acid receptor antagonist bicuculline, the glycinergic antagonist strychnine, and the type 3 serotonin receptor antagonist ICS-205,930 block ACh-evoked currents in α9-injected Xenopus laevis oocytes with the following rank order of potency: strychnine > ICS-205,930 > bicuculline. Block by antagonists was reflected in an increase in the acetylcholine (ACh) EC50 value, with no changes in agonist maximal response or Hill coefficient, which suggests a competitive type of block. Moreover, whereas neither γ-aminobutyric acid nor glycine modified ACh-evoked currents, serotonin blocked responses to ACh in a concentration-dependent manner. The present results suggest that the α9 nAChR must conserve in its primary structure some residues responsible for ligand binding common to other Cys-loop receptors. In addition, it adds further evidence that the α9 nAChR and the cholinergic receptor present at the base of cochlear outer hair cells have similar pharmacological properties.