Study of the calcium dynamics of the human α4β2, α3β4 and α1β1γδ nicotinic acetylcholine receptors

Abstract

In this study three major subtypes of nicotinic acetylcholine receptors were characterized pharmacologically using the calcium influx through the ion channel as a robust functional assay system. Human α3β4 receptors and α4β2 receptors were cloned and stably expressed in HEK293 cells. [125I]epibatidine saturation binding yielded a Bmax of 4420±840 fmol/mg protein for the α4β2 receptor (n=4) and 518±15 fmol/mg protein for the α3β4 receptor (n=4). As a source for muscle type of nicotinic receptor, the TE671 cell line was used which expresses endogenously the human fetal α1β1γδ subtype of nicotinic receptor. Stimulation of these nicotinic receptor subtypes in the different cell lines led to calc..