Related Experiment Video
Updated: Sep 27, 2026

Isolation of Human Atrial Myocytes for Simultaneous Measurements of Ca2+ Transients and Membrane Currents
Published on: July 3, 2013
Differential sensitivity of atrial and ventricular K(ATP) channels to metabolic inhibition
Serge Poitry1, Laurianne van Bever, Fabrice Coppex
1Department of Physiology, Centre Médical Universitaire, Université de Genève, 1 rue Michel-Servet, 1211 Geneva 4, Switzerland.
Objective:
The aim is to compare the activation of ATP-sensitive potassium channels (K(ATP) channels) in intact and metabolically impaired atrial and ventricular myocytes.
Methods:
The K(ATP) channel current is measured by whole cell and gramicidin-perforated patch clamp recordings in 164 cultured neonate rat cardiomyocytes.
Results:
In whole cell recordings with 84 micromol/l ADP in pipette, spontaneous activity is significantly higher in atrium than ventricle, and EC(50) for the K(ATP) channel opener diazoxide is 0.13 micromol/l (atrium) versus 3.1 micromol/l (ventricle). With an ATP-regenerating system in pipette, EC(50) for diazoxide is 19.7 micromol/l (atrium) versus 54.9 micromol/l (ventricle). In gramicidin-perforated patch recordings, atrial myocytes respond significantly to 100 nmol/l of the mitochondrial protonophore CCCP, while ventricular myocytes do not. EC(50) for diazoxide is 129 micromol/l (atrium) versus >2500 micromol/l (ventricle) for myocytes exposed to CCCP, and 676 versus >2500 micromol/l, respectively, without CCCP.
Conclusions:
(1) K(ATP) channels are significantly more sensitive to metabolic inhibition in atrial than ventricular myocytes. (2) Sensitivity of atrium versus ventricle to the channel opener diazoxide increases from 3:1 to > or = 24:1 with ADP or metabolic inhibition. If extended to intact hearts, the results would predict a higher atrial sensitivity to ischemia, and a high sensitivity of the ischemic atrium to K(ATP) channel openers.
More Related Videos
08:11Voltage-Dependent Potassium Current Recording on H9c2 Cardiomyocytes via the Whole-Cell Patch-Clamp Technique
Published on: November 11, 2022
12:48Measuring Cation Transport by Na,K- and H,K-ATPase in Xenopus Oocytes by Atomic Absorption Spectrophotometry: An Alternative to Radioisotope Assays
Published on: February 19, 2013
Related Concept Videos
G-Protein Gated Ion Channels
Sensory organs,...
ATP Driven Pumps I: An Overview
There are four main types of ATP-driven pumps - P-type, V-type, F-type, and ABC transporter. All these pumps are of varying complexities and are...
ATP Driven Pumps III: V-type Pumps
The peripheral or cytosolic V1 domain with eight subunits is involved in ATP hydrolysis. The integral or transmembrane V0 domain containing at least five subunits...
ATP Synthase: Mechanism