Assay of muscarinic acetylcholine receptor function in cultured cardiac cells by stimulation of /sup 86/Rb+ efflux

Journal Article · Sun Sep 01 00:00:00 EDT 1985 · Anal. Biochem.; (United States)

DOI:https://doi.org/10.1016/0003-2697(85)90588-3· OSTI ID:5809638

Hunter, D D; Nathanson, N M

An assay for the increase in potassium permeability mediated by muscarinic acetylcholine receptors (mAChR) in cultured cardiac cells is described, using the K+ ion substitute /sup 86/Rb+ as the tracer ion. Cardiac cells accumulate /sup 86/Rb+ from the extracellular medium in a Na+/K+ ATPase-dependent manner. Subsequent efflux of /sup 86/Rb+ in the absence and presence of muscarinic agonists follows kinetics similar to those previously reported for /sup 42/K+. The mAChR agonist carbamylcholine (carbachol) stimulated /sup 86/Rb+ efflux with an EC50 of 50 nM. The half-time for efflux is reduced by greater than 40% at maximally effective concentrations of agonist. Stimulation of /sup 86/Rb+ efflux by carbachol is blocked by the mAChR antagonist atropine with an IC50 of 15 nM. The stimulation of 86Rb+ efflux by carbachol is not affected by the presence of the Na+/K+ ATPase inhibitor ouabain. This assay provides a method for quantitating the mAChR-mediated increase in K+ permeability in cardiac cells without the use of /sup 42/K+.

• OSTI ID: 5809638
• Journal Information: Anal. Biochem.; (United States), Vol. 2
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ACETYLCHOLINE
RECEPTORS
CELL MEMBRANES
PERMEABILITY
ATP-ASE
ATROPINE
BIOASSAY
BIOCHEMICAL REACTION KINETICS
CELL CULTURES
MYOCARDIUM
POTASSIUM
POTASSIUM 42
RUBIDIUM 86
TRACER TECHNIQUES
ACID ANHYDRASES
ALKALI METAL ISOTOPES
ALKALI METALS
ALKALOIDS
AMINES
AMMONIUM COMPOUNDS
AUTONOMIC NERVOUS SYSTEM AGENTS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CARDIOVASCULAR SYSTEM
CELL CONSTITUENTS
DAYS LIVING RADIOISOTOPES
DRUGS
ELEMENTS
ENZYMES
ESTERS
HEART
HOURS LIVING RADIOISOTOPES
HYDROLASES
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MEMBRANE PROTEINS
MEMBRANES
METALS
MINUTES LIVING RADIOISOTOPES
MUSCLES
NEUROREGULATORS
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANS
PARASYMPATHOLYTICS
PARASYMPATHOMIMETICS
PHOSPHOHYDROLASES
POTASSIUM ISOTOPES
PROTEINS
QUATERNARY COMPOUNDS
RADIOISOTOPES
REACTION KINETICS
RUBIDIUM ISOTOPES
550201* - Biochemistry- Tracer Techniques