Featured Research

from universities, journals, and other organizations

Ion channels ensure the heart keeps time

Date:
September 11, 2011
Source:
Ludwig-Maximilians-Universitaet Muenchen (LMU)
Summary:
Electrical signals regulate the rhythmic contractions of the heart muscle and thus control heartbeat. If the signals go awry, the consequences can be lethal. Researchers have now delineated how specific ion channels in the membranes of cardiomyocytes ensure that the heart beats in and on time.

Electrical signals regulate the rhythmic contractions of the heart muscle and thus control heartbeat. If the signals go awry, the consequences can be lethal. LMU researchers have now delineated how specific ion channels in the membranes of cardiomyocytes ensure that the heart beats in and on time.

The heartbeat is the result of rhythmic contractions of the heart muscle, which are in turn regulated by electrical signals called action potentials. Action potentials result from the controlled flow of ions into heart muscle cells (depolarization) through channels in their membranes, and are followed by a compensating reverse ion current (repolarization), which restores the original state. If the duration of the repolarization phase is not just right, the risk of ventricular arrhythmia and sudden cardiac death increases significantly.

Research groups led by Professors Martin Biel and Christian Wahl-Schott at the Department of Pharmacy at LMU Munich have now described a new function of the so-called HCN channels in the heart. Four subtypes of HCN channels are known, which are essential for the repolarization phase. The ion current that passes through these channels is often referred to as the pacemaker current, because it is instrumental for the control of heartbeat.

"It has been known for a long time that members of this family of ion channels are present in the pacemaker cells in the sinoatrial node of the heart. These cells display spontaneous electrical activity, and it was known that their HCN channels contribute to an increase in the heart rate under certain conditions," says Wahl-Schott. "However, the role of the HCN channels in the normal contractile function of the heart muscle has been unclear."

Using a new animal model, in which one of the subtypes of HCN channel proteins (HCN3) is missing, the researchers observed a significant reduction in the duration of the repolarization phase that follows the action potential in the portion of the myocardium that undergoes active contractions.

"Our results demonstrate that HCN channels are important for normal repolarization," says Biel. "And that is a completely new physiological concept, which underlines the biomedical relevance of these channels - and can perhaps be exploited therapeutically."


Story Source:

The above story is based on materials provided by Ludwig-Maximilians-Universitaet Muenchen (LMU). Note: Materials may be edited for content and length.


Journal Reference:

  1. Stefanie Fenske et al. HCN3 contributes to the ventricular action potential waveform in the murine heart. Circulation Research, 8 September 2011 DOI: 10.1161/CIRCRESAHA.111.246173

Cite This Page:

Ludwig-Maximilians-Universitaet Muenchen (LMU). "Ion channels ensure the heart keeps time." ScienceDaily. ScienceDaily, 11 September 2011. <www.sciencedaily.com/releases/2011/09/110909074918.htm>.
Ludwig-Maximilians-Universitaet Muenchen (LMU). (2011, September 11). Ion channels ensure the heart keeps time. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/2011/09/110909074918.htm
Ludwig-Maximilians-Universitaet Muenchen (LMU). "Ion channels ensure the heart keeps time." ScienceDaily. www.sciencedaily.com/releases/2011/09/110909074918.htm (accessed July 29, 2014).

Share This




More Health & Medicine News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Ebola Virus Threatens West Africa

Deadly Ebola Virus Threatens West Africa

AP (July 28, 2014) West African nations and international health organizations are working to contain the largest Ebola outbreak in history. It's one of the deadliest diseases known to man, but the CDC says it's unlikely to spread in the U.S. (July 28) Video provided by AP
Powered by NewsLook.com
$15B Deal on Vets' Health Care Reached

$15B Deal on Vets' Health Care Reached

AP (July 28, 2014) A bipartisan deal to improve veterans health care would authorize at least $15 billion in emergency spending to fix a veterans program scandalized by long patient wait times and falsified records. (July 28) Video provided by AP
Powered by NewsLook.com
Two Americans Contract Ebola in Liberia

Two Americans Contract Ebola in Liberia

Reuters - US Online Video (July 28, 2014) Two American aid workers in Liberia test positive for Ebola while working to combat the deadliest outbreak of the virus ever. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins