Functional characterization of mouse α4β2 nicotinic acetylcholine receptors stably expressed in HEK293T cells

• DOI: 10.1111/j.1471-4159.2004.02801.x
• Publication Date: 2004-11-18T17:56:31Z
• Authors: Mark S. Karadsheh; M. Salman Shah; Xin Tang; Robert L. Macdonald; Jerry A. Stitzel
• Keywords: Methyllycaconitine; Nicotinic Antagonist; HEK 293 cells; Calcium in biology

Abstract Mouse α4β2 nicotinic acetylcholine receptors (nAchRs) were stably expressed in HEK293T cells. The function of this stable cell line, termed mmα4β2, was assessed using an aequorin‐based luminescence method that measures agonist‐evoked changes intracellular calcium. Agonist‐elicited calcium due primarily to direct entry through the channel, although release from stores contributed ˜ 28% response. Agonist pharmacologies very similar between mmα4β2 cells and most lines express human nAchRs. Based on agonist profiles sensitivity antagonist dihydro‐β‐erythroidine (DHβE), predominant nAchR exhibits a pharmacology resembles DHβE‐sensitive component 86 Rb + efflux mouse brain synaptosomes. However, when evaluated with aequorin assay, found be atypically sensitive blockade by presumed α7‐selective methyllycaconitine (MLA), exhibiting IC 50 value 31 ± 0.1 n m . Similar values have been reported for MLA inhibition nicotine‐stimulated dopamine release, response is mediated β2‐subunit‐containing nAchRs not α7‐subunit‐containing Consequently, at low nanomolar concentrations, may as selective α7‐containing previously thought.