Related Experiment Video
Updated: Sep 25, 2026

Contractility Measurements on Isolated Papillary Muscles for the Investigation of Cardiac Inotropy in Mice
Published on: September 17, 2015
Magnesium in cardiac energy metabolism
Abstract:
Free intracellular magnesium ion, which influences many metabolic processes, is the subject of ongoing research. Its concentration has been difficult to measure because the available methods, including dye injection, microelectrodes, and nuclear magnetic resonance measurements, are invasive or indirect. Concentrations ranging from 0.1 mM in frog muscle to 6 mM in barnacle muscle have been reported. We describe recent experimental evidence regarding the concentration of free intracellular magnesium and consider the limitations of these methods. A substantial body of evidence, including our models of cardiac energy metabolism and its magnesium-related processes, indicates that intracellular concentrations of free magnesium are low (ca. 0.4 mM) and vary with time and conditions.
More Related Videos
Related Concept Videos
Structure of Cardiac Muscles
Compared to skeletal muscles, cardiac muscle cells are small and mostly have a single nucleus. Additionally, they are usually...
Specialized Characteristics of Cardiac Muscles
Cardiac muscle cells are smaller than skeletal muscles, averaging 10–20 mm in diameter and 50–100 mm in length. However, they have large energy demands for continuous contraction and relaxation. This energy is almost exclusively derived from aerobic metabolism of energy reserves in...
Electrophysiology of Normal Cardiac Rhythm
Pathophysiology of Cardiac Performance
Heart Failure Drugs: Inotropic Agents
Cardiac Action Potential
The cardiac action potential process involves a series of phases characterized by the movement of ions across the cardiac cell membranes, leading to the depolarization and repolarization of the cardiac myocytes.
Ionic Basis of Cardiac Action Potentials

