Isotopic rubidium ion efflux assay for the functional characterization of nicotinic acetylcholine receptors on clonal cell lines

Journal Article · Tue Nov 15 04:00:00 EST 1988 · Anal. Biochem.; (United States)

DOI:https://doi.org/10.1016/0003-2697(88)90380-6· OSTI ID:5905137

Lukas, R J; Cullen, M J

An isotopic rubidium ion efflux assay has been developed for the functional characterization of nicotinic acetylcholine receptors on cultured neurons. This assay first involves the intracellular sequestration of isotopic potassium ion analog by the ouabain-sensitive action of a sodium-potassium ATPase. Subsequently, the release of isotopic rubidium ion through nicotinic acetylcholine receptor-coupled monovalent cation channels is activated by application of nicotinic agonists. Specificity of receptor-mediated efflux is demonstrated by its sensitivity to blockade by nicotinic, but not muscarinic, antagonists. The time course of agonist-mediated efflux, within the temporal limitations of the assay, indicates a slow inactivation of receptor function on prolonged exposure to agonist. Dose-response profiles (i) have characteristic shapes for different nicotinic agonists, (ii) are described by three operationally defined parameters, and (iii) reflect different affinities of agonists for binding sites that control receptor activation and functional inhibition. The rubidium ion efflux assay provides fewer hazards but greater sensitivity and resolution than isotopic sodium or rubidium ion influx assays for functional nicotinic receptors.

• Research Organization: Barrow Neurological Institute, Phoenix, AZ (USA)
• OSTI ID: 5905137
• Journal Information: Anal. Biochem.; (United States), Journal Name: Anal. Biochem.; (United States) Vol. 175:1; ISSN ANBCA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ACETYLCHOLINE
ACID ANHYDRASES
AFFINITY
ALKALI METAL ISOTOPES
AMINES
AMMONIUM COMPOUNDS
ANIMAL CELLS
ATP-ASE
AUTONOMIC NERVOUS SYSTEM AGENTS
DOSE-RESPONSE RELATIONSHIPS
DRUGS
ENZYMES
ESTERS
HYDROLASES
ISOTOPE APPLICATIONS
ISOTOPES
MEMBRANE PROTEINS
MEMBRANE TRANSPORT
NERVE CELLS
NEUROREGULATORS
ORGANIC COMPOUNDS
PARASYMPATHOMIMETICS
PHOSPHOHYDROLASES
PROTEINS
QUATERNARY COMPOUNDS
RADIOASSAY
RECEPTORS
RUBIDIUM ISOTOPES
SOMATIC CELLS
SPECIFICITY
TRACER TECHNIQUES