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 April 20, 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 April 20, 2014).

Share This



More Health & Medicine News

Sunday, April 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Nine-Month-Old Baby Can't Open His Mouth

Nine-Month-Old Baby Can't Open His Mouth

Newsy (Apr. 19, 2014) Nine-month-old Wyatt Scott was born with a rare disorder called congenital trismus, which prevents him from opening his mouth. Video provided by Newsy
Powered by NewsLook.com
'Holy Grail' Of Weight Loss? New Find Could Be It

'Holy Grail' Of Weight Loss? New Find Could Be It

Newsy (Apr. 18, 2014) In a potential breakthrough for future obesity treatments, scientists have used MRI scans to pinpoint brown fat in a living adult for the first time. Video provided by Newsy
Powered by NewsLook.com
Little Progress Made In Fighting Food Poisoning, CDC Says

Little Progress Made In Fighting Food Poisoning, CDC Says

Newsy (Apr. 18, 2014) A new report shows rates of two foodborne infections increased in the U.S. in recent years, while salmonella actually dropped 9 percent. Video provided by Newsy
Powered by NewsLook.com
Scientists Create Stem Cells From Adult Skin Cells

Scientists Create Stem Cells From Adult Skin Cells

Newsy (Apr. 17, 2014) The breakthrough could mean a cure for some serious diseases and even the possibility of human cloning, but it's all still a way off. 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