Pharmacology of the agonist binding sites of rat neuronal nicotinic receptor subtypes expressed in HEK 293 cells

The binding affinities of agonists at heteromeric nicotinic receptors composed of rat α2, α3 and α4 subunits in combination with β2 or β4 subunits were examined in stably transfected HEK 293 cells. In most cases, the affinities of agonists were higher at receptors composed of an α subunit in combination with the β2 subunit than the β4 subunit, and in some cases this difference was quite large (>250 times), suggesting the possibility of developing subtype-selective ligands and therapeutically useful drugs.