Featured Research

from universities, journals, and other organizations

Abnormal Heartbeats Caused By Changes In Ion Channel Density

Date:
August 28, 2009
Source:
Journal of Clinical Investigation
Summary:
Two independent studies have determined how changes in the density of different ion channels in the surface membrane of heart muscle cells can lead to life-threatening abnormal heartbeats.

Two independent studies have determined how changes in the density of different ion channels in the surface membrane of heart muscle cells can lead to life-threatening abnormal heartbeats, according to research to be published in the August 24 issue of the Journal of Clinical Investigation.

Related Articles


As Gail Robertson, at the University of Wisconsin — Madison, discusses in an accompanying commentary, these important studies provide new insight into the complex array of mechanisms controlling our heartbeat and how they can be perturbed.

The coordinated contraction of heart muscle cells that ensures a normal heartbeat is controlled by an electrical current that passes from one heart muscle cell to the next and along a special conduction system within the heart. A block in conduction of this electrical current disrupts the heartbeat and is the most common cause of pacemaker implantation. Many diseases that cause conduction block, including progressive familial heart block type I (PFHBI), are inherited. Olaf Pangs and colleagues, at Universitδt Hamburg, Germany, have now linked a mutation in the gene TRPM4 with PFHBI in 3 branches of a large South African Afrikaner pedigree with the disease. The TRPM4 gene is responsible for generating an ion channel that the authors found to be expressed at highest levels in a crucial region of the special conduction system within the human heart. Importantly, the PFHBI-associated mutation increased levels of the TRPM4 channel at the cell surface and blunted conduction of the electrical current.

A noninherited cause of an abnormal heartbeat is low levels of potassium (K+) in the blood, which can trigger life-threatening changes to the heartbeat. Shetuan Zhang and colleagues, at Queen's University, Ontario, have now determined in rabbits that low levels of potassium in the blood cause decreased levels of the IKr ion channel at the surface of rabbit heart muscle cells. Specifically, low levels of potassium caused increased internalization and degradation of the channels. Similarly, low levels of potassium in culture medium decreased levels of the human counterpart, HERG, in cell lines. These data provide insight into how a drop in levels of potassium in the blood can cause sudden cardiac death.


Story Source:

The above story is based on materials provided by Journal of Clinical Investigation. Note: Materials may be edited for content and length.


Journal References:

  1. Kruse et al. Impaired endocytosis of the ion channel TRPM4 is associated with human progressive familial heart block type I. Journal of Clinical Investigation, 2009; DOI: 10.1172/JCI38292
  2. Guo et al. Extracellular K concentration controls cell surface density of IKr in rabbit hearts and of the HERG channel in human cell lines. Journal of Clinical Investigation, 2009; DOI: 10.1172/JCI39027
  3. Gail A. Robertson. Endocytic control of ion channel density as a target for cardiovascular disease. Journal of Clinical Investigation, 2009; DOI: 10.1172/JCI40427

Cite This Page:

Journal of Clinical Investigation. "Abnormal Heartbeats Caused By Changes In Ion Channel Density." ScienceDaily. ScienceDaily, 28 August 2009. <www.sciencedaily.com/releases/2009/08/090825085530.htm>.
Journal of Clinical Investigation. (2009, August 28). Abnormal Heartbeats Caused By Changes In Ion Channel Density. ScienceDaily. Retrieved November 26, 2014 from www.sciencedaily.com/releases/2009/08/090825085530.htm
Journal of Clinical Investigation. "Abnormal Heartbeats Caused By Changes In Ion Channel Density." ScienceDaily. www.sciencedaily.com/releases/2009/08/090825085530.htm (accessed November 26, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Wednesday, November 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

Newsy (Nov. 25, 2014) — The US FDA is announcing new calorie rules on Tuesday that will require everywhere from theaters to vending machines to include calorie counts. Video provided by Newsy
Powered by NewsLook.com
Daily Serving Of Yogurt Could Reduce Risk Of Type 2 Diabetes

Daily Serving Of Yogurt Could Reduce Risk Of Type 2 Diabetes

Newsy (Nov. 25, 2014) — Need another reason to eat yogurt every day? Researchers now say it could reduce a person's risk of developing type 2 diabetes. Video provided by Newsy
Powered by NewsLook.com
Madagascar Working to Contain Plague Outbreak

Madagascar Working to Contain Plague Outbreak

AFP (Nov. 24, 2014) — Madagascar said Monday it is trying to contain an outbreak of plague -- similar to the Black Death that swept Medieval Europe -- that has killed 40 people and is spreading to the capital Antananarivo. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com
Are Female Bosses More Likely To Be Depressed?

Are Female Bosses More Likely To Be Depressed?

Newsy (Nov. 24, 2014) — A new study links greater authority with increased depressive symptoms among women in the workplace. 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:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

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