Related Experiment Video
Updated: Jul 13, 2026
12:10
Measuring Fast Calcium Fluxes in Cardiomyocytes
Published on: November 29, 2011
Atrial glutathione content, calcium current, and contractility.
Cynthia A Carnes1, Paul M L Janssen, Mary L Ruehr
1College of Pharmacy, Ohio State University, Columbus, Ohio 43210, USA.
The Journal of Biological Chemistry
|July 28, 2007
Summary
Reduced glutathione levels in atrial fibrillation (AF) patients correlate with decreased calcium current. Supplementing glutathione precursors or glutathione restored this current, suggesting a therapeutic target for AF.
Area of Science:
- Cardiology
- Molecular Biology
- Biochemistry
Background:
- Atrial fibrillation (AF) is associated with reduced L-type calcium current (I(Ca,L)) in atrial myocytes, impacting contractility.
- Oxidant stress and altered calcium channel function are implicated in AF pathophysiology.
Purpose of the Study:
- To investigate the relationship between glutathione levels and I(Ca,L) in atrial tissue from AF patients.
- To explore the potential role of S-nitrosylation in mediating the effects of glutathione on I(Ca,L).
Main Methods:
- Measurement of left atrial glutathione content in AF patients and controls.
- Assessment of I(Ca,L) in atrial myocytes from AF patients and dogs treated with glutathione synthesis inhibitors.
- Evaluation of S-nitrosylation of calcium channels using the biotin switch technique.
Main Results:
- Glutathione levels were significantly lower in AF patients compared to controls.
- N-acetylcysteine treatment increased I(Ca,L) in AF patient myocytes; buthionine sulfoximine treatment reduced I(Ca,L) and contractility in canine atria.
- Exogenous glutathione restored I(Ca,L) in canine myocytes; S-nitrosylation of calcium channels was observed in AF tissues and inversely correlated with glutathione content.
Conclusions:
- Decreased atrial glutathione content is linked to reduced I(Ca,L) in atrial fibrillation.
- Glutathione depletion may contribute to AF pathophysiology via S-nitrosylation-mediated attenuation of calcium channels.
- Restoration of glutathione levels may represent a therapeutic strategy for atrial fibrillation.
More Related Videos
10:53Isolation of Human Atrial Myocytes for Simultaneous Measurements of Ca2+ Transients and Membrane Currents
Published on: July 3, 2013
06:22Isolation of High Quality Murine Atrial and Ventricular Myocytes for Simultaneous Measurements of Ca2+ Transients and L-Type Calcium Current
Published on: November 3, 2020
Related Concept Videos
01:25Smooth Muscle Contraction
Smooth muscle contraction is a complex process vital for various bodily functions, from maintaining blood vessel tension to facilitating the movement of food through the digestive tract. Unlike striated muscles, smooth muscle contraction begins more slowly and lasts longer.
The onset of contraction is triggered by an increase in calcium ions within the sarcoplasm, similar to the process in striated muscle. However, smooth muscles have a relatively smaller reservoir of the sarcoplasmic...
The onset of contraction is triggered by an increase in calcium ions within the sarcoplasm, similar to the process in striated muscle. However, smooth muscles have a relatively smaller reservoir of the sarcoplasmic...
01:21G-Protein Gated Ion Channels
GPCRs are primarily responsible for our sense of smell, taste, and vision. The binding of a sensory stimulus activates GPCR to stimulate effector proteins, many of which are ion channels in the sensory organs. GPCRs modulate the opening and closing of the target ion channels either directly by binding them, or by releasing second messengers that activate these channels. As ions move across the membrane, the membrane potential is altered, which induces an appropriate response.
Sensory organs,...
Sensory organs,...
01:20Antiarrhythmic Drugs: Class IV Agents as Calcium Channel Blockers
Class IV antiarrhythmic drugs, such as verapamil and diltiazem, block calcium channels. They primarily affect the heart, slowing the conduction in calcium-dependent tissues like the SA and AV nodes. These drugs manage reentrant supraventricular tachycardia (SVT) and reduce ventricular rate in atrial flutter/fibrillation.
Verapamil, a calcium channel blocker, inhibits calcium movement across myocardial cell membranes and vascular smooth muscle. This results in the dilation of coronary and...
Verapamil, a calcium channel blocker, inhibits calcium movement across myocardial cell membranes and vascular smooth muscle. This results in the dilation of coronary and...
01:26Heart Failure Drugs: Inotropic Agents
Positive inotropic agents are commonly used as the first line of treatment for heart failure. One such agent is digoxin, derived from the genus Digitalis, which has been known for centuries but effectively utilized since 1785. However, these cardiac glycosides can have potentially toxic effects due to their mechanism of action, which involves inhibiting Na+/K+-ATPase and increasing contractility. Digoxin is absorbed orally and distributed in various tissues, including the CNS. It has a long...
01:19Electrophysiology of Normal Cardiac Rhythm
The normal cardiac rhythm is a synchronized electrical activity that facilitates the regular and coordinated contraction of the heart muscle. This process is essential for efficient blood circulation throughout the body. The fundamental elements involved in establishing and maintaining this rhythm include the unique electrical properties of cardiac muscle cells, the sinoatrial (SA) node's pacemaker function, the specialized conducting system, and the ionic mechanisms underlying each phase of...
01:27Feedback Regulation of Calcium Concentration
Calcium is an essential signaling molecule required for various cellular functions. Calcium pumps and ion channels on cell and organellar membranes, such as those on the endoplasmic reticulum (ER), regulate calcium concentrations inside the cell. They remain closed, keeping the cytosolic calcium levels low at a resting state.
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...