Related Experiment Video
Updated: Jul 17, 2026

Patch Clamp and Perfusion Techniques for Studying Ion Channels Expressed in Xenopus oocytes
Published on: January 10, 2011
Effects of intracellular magnesium on calcium, potassium and chloride channels
E Kelepouris1, R Kasama, Z S Agus
1Department of Physiology, University of Pennsylvania, Philadelphia 19104.
Abstract:
Intracellular free magnesium activity approximates 0.6-0.8 mM. Variations in concentration around this physiologic range profoundly affect current flow through calcium, potassium and chloride channels. These effects are exerted on both inwardly and outwardly directed currents and appear to be independent of the state of phosphorylation of the channel. In the heart, these effects are manifested in changes in action potential duration, which may help to explain postulated links between hypomagnesemia and arrhythmias. In the kidney, effects of magnesium on ion channels may subserve a protective role and may explain how potassium balance is altered in magnesium depletion syndromes.
Related Concept Videos
The Role of Ion Channels in Neuronal Computation
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential.
Voltage-gated Ion Channels
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...
Feedback Regulation of Calcium Concentration
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Calmodulin-dependent Signaling
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
Ligand-Gated Ion Channel Receptor: Gating Mechanism
Voltage-gated Ion Channels
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...

