Featured Research

from universities, journals, and other organizations

Understanding the heart's rhythm

Date:
June 11, 2013
Source:
American Friends of Tel Aviv University
Summary:
Scientists have discovered a previously unidentified potassium channel in cardiac cells that regulate the human heartbeat. This could be a significant step towards developing "biological pacemakers" to replace today's mechanical pacemakers, the researcher says.

The heart's regular rhythm is crucial to the delivery of oxygenated blood and nutrients to all the organs of the body. It is regulated by a bundle of cells called "the pacemaker," which use electrical signals to set the pace of the heart. Dysfunction in this mechanism can lead to an irregular heartbeat, known as arrhythmia, and often necessitates the implantation of an artificial pacemaker.

Previously, scientists found that many cases of inherited arrhythmias originating in the pacemaker could be attributed to functional defects in the channels responsible for the flow of sodium and calcium. Now Prof. Bernard Attali of Tel Aviv University's Sackler Faculty of Medicine and his fellow researchers have discovered a previously unidentified potassium channel in the cardiac pacemaker which helps to regulate the heartbeat. He hypothesizes that some cases of unexplained arrhythmia could be traced back to irregularities in this channel.

Developing therapies to target this potassium channel could be a significant step towards circumventing artificial pacemakers in favor of biological options, says Prof. Attali. This research has been reported in the journal PNAS.

A cellular heart model

To further investigate the workings of the biological pacemaker, Prof. Attali and his fellow researchers turned to embryonic stem cells isolated from human subjects. Once coaxed into differentiating into cardiac tissue, these cells began to beat automatically, like a small human heart.

While observing and recording the cells' electrical activity, researchers discovered the existence of a new channel in the pacemaker. Facilitating the flow of potassium from the pacemaker cells, this channel triggers the repolarization of the cells -- returning the cell membrane from a "beating" to a "resting" state -- and automatically renews or "restarts" the cycling of the heart.

Since discovering this channel in the embryonic heart, the researchers have shown that the channel exists in the adult heart as well. This finding deepens medicine's understanding of the heart's pacemaker function, which has been the subject of scientific research for over a century.

Screening for mutations

The next step is to conduct screening for mutations in the gene encoding the potassium channel, a process already underway at the TAU-affiliated Sheba Medical Center. "We would like to understand if there are genetic diseases linked to this channel," such as a previously unknown cause of arrhythmia, explains Prof. Attali. If a mutation is found, researchers can begin the hunt for drug compounds, which target this channel. The ultimate goal, he adds, is to be able to treat heart arrhythmias biologically by altering the properties of the pacemaker bundle, rather than relying on a human-made electric pacemaker.

One possible solution could be transplanting healthy pacemaker cells -- developed from a patient's own stem cells -- to replace dysfunctional cells and restore proper heart rhythm. This method would circumvent a common risk of the body rejecting a mechanical transplant.


Story Source:

The above story is based on materials provided by American Friends of Tel Aviv University. Note: Materials may be edited for content and length.


Journal Reference:

  1. D. Weisbrod, A. Peretz, A. Ziskind, N. Menaker, S. Oz, L. Barad, S. Eliyahu, J. Itskovitz-Eldor, N. Dascal, D. Khananshvili, O. Binah, B. Attali. SK4 Ca2 activated K channel is a critical player in cardiac pacemaker derived from human embryonic stem cells. Proceedings of the National Academy of Sciences, 2013; 110 (18): E1685 DOI: 10.1073/pnas.1221022110

Cite This Page:

American Friends of Tel Aviv University. "Understanding the heart's rhythm." ScienceDaily. ScienceDaily, 11 June 2013. <www.sciencedaily.com/releases/2013/06/130611122105.htm>.
American Friends of Tel Aviv University. (2013, June 11). Understanding the heart's rhythm. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2013/06/130611122105.htm
American Friends of Tel Aviv University. "Understanding the heart's rhythm." ScienceDaily. www.sciencedaily.com/releases/2013/06/130611122105.htm (accessed July 24, 2014).

Share This




More Health & Medicine News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Condemned Man's US Execution Takes Nearly Two Hours

Condemned Man's US Execution Takes Nearly Two Hours

AFP (July 24, 2014) America's death penalty debate raged Thursday after it took nearly two hours for Arizona to execute a prisoner who lost a Supreme Court battle challenging the experimental lethal drug cocktail. Duration: 00:55 Video provided by AFP
Powered by NewsLook.com
China's Ageing Millions Look Forward to Bleak Future

China's Ageing Millions Look Forward to Bleak Future

AFP (July 24, 2014) China's elderly population is expanding so quickly that children struggle to look after them, pushing them to do something unexpected in Chinese society- move their parents into a nursing home. Duration: 02:07 Video provided by AFP
Powered by NewsLook.com
Hundreds in Virginia Turn out for a Free Clinic to Manage Health

Hundreds in Virginia Turn out for a Free Clinic to Manage Health

AFP (July 24, 2014) America may be the world’s richest country, but in terms of healthcare, the World Health Organisation ranks it 37th - prompting hundreds in Virginia to turn out for a free clinic run by “Remote Area Medical”. Duration 02:40 Video provided by AFP
Powered by NewsLook.com
Idaho Boy Helps Brother With Disabilities Complete Triathlon

Idaho Boy Helps Brother With Disabilities Complete Triathlon

Newsy (July 23, 2014) An 8-year-old boy helped his younger brother, who has a rare genetic condition that's confined him to a wheelchair, finish a triathlon. Video provided by Newsy
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