Featured Research

from universities, journals, and other organizations

Researchers Discover New Function Of Cardiac Sodium Pump

Date:
January 15, 2007
Source:
Max Delbruck Center For Molecular Medicine
Summary:
Scientists at the Max Delbrück Center for Molecular Medicine Berlin-Buch have discovered a new function of the cardiac sodium pump. During embryonic heart morphogenesis, the pump generates a change in the ion concentration within and outside the cells (ion gradient). The scientists were able to demonstrate that the ion gradient determines the top (apical) and bottom (basal) of heart cell surfaces. Scientists call this cell polarity, a phenomenon vital for heart function.

The heart can only beat if electrically charged particles (ions) are transported back and forth across the plasma membrane of the heart cells. The sodium-potassium pump conducts this transport activity by pumping potassium ions into the cell interior and allowing sodium ions to flow out of the cell. Indirectly, it also regulates the concentration of calcium ions, which in turn control heartbeat. Patients with cardiac insufficiency receive drugs that affect the sodium pump in order to stabilize their heartbeat.

Now, scientists at the Max Delbrück Center for Molecular Medicine (MDC) Berlin-Buch have discovered a new function of the sodium pump. During embryonic heart morphogenesis, the pump generates a change in the ion concentration within and outside the cells (ion gradient). The scientists were able to demonstrate that the ion gradient determines the top (apical) and bottom (basal) of heart cell surfaces. Scientists call this cell polarity, a phenomenon vital for heart function.

The sodium pump is also involved in cell junction maintenance, thus ensuring that the heart cells stay connected with one another. Without this sodium pump, the heart never develops. A report of the findings of PhD student Elena Cibrián-Uhalte and Dr. Salim Abdelilah-Seyfried (both MDC) and researchers of the University of California Los Angeles, USA has now been published in the Journal of Cell Biology (Jan. 15, 2007; 176, 2)*.

To date, cell biologists have identified a number of signal pathways which regulate organ development. "What is new and very surprising about this discovery is that ion gradients generated by the sodium pump regulate these fundamental cell biological processes, namely cell polarization and cell junction maintenance," said Dr. Seyfried, developmental biologist at MDC. He directs a laboratory that studies vertebrate development by using the zebrafish among other model systems. Zebrafish are only a few centimeters in length and their embryos are transparent, enabling researchers to observe each cell under the microscope.

Dr. Seyfried is especially interested in how epithelial cells on the outer and inner surfaces of the body polarize during organ development. This cell polarity is essential for organ functioning. "The most important finding of our present study is that the ion gradient regulates cell polarity," he said. "But we still need to find out exactly how ion gradients affect the polarization of myocardial cells during their early development. Moreover," he added, "for technical reasons, it is not possible for us to measure the ion concentrations in tiny (zebrafish) hearts that are only a few micrometers across."

The scientists in Berlin suspect that the defects in the sodium pump not only affect myocardial cell junction maintenance but also the development of the blood-brain barrier and the retina. If this hypothesis is confirmed, this means that the sodium pump plays a central role in the development of different types of epithelial cells not only in the heart but throughout the entire organism.


Story Source:

The above story is based on materials provided by Max Delbruck Center For Molecular Medicine. Note: Materials may be edited for content and length.


Cite This Page:

Max Delbruck Center For Molecular Medicine. "Researchers Discover New Function Of Cardiac Sodium Pump." ScienceDaily. ScienceDaily, 15 January 2007. <www.sciencedaily.com/releases/2007/01/070115100535.htm>.
Max Delbruck Center For Molecular Medicine. (2007, January 15). Researchers Discover New Function Of Cardiac Sodium Pump. ScienceDaily. Retrieved July 30, 2014 from www.sciencedaily.com/releases/2007/01/070115100535.htm
Max Delbruck Center For Molecular Medicine. "Researchers Discover New Function Of Cardiac Sodium Pump." ScienceDaily. www.sciencedaily.com/releases/2007/01/070115100535.htm (accessed July 30, 2014).

Share This




More Health & Medicine News

Wednesday, July 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Generics Eat Into Pfizer's Sales

Generics Eat Into Pfizer's Sales

Reuters - Business Video Online (July 29, 2014) — Pfizer, the world's largest drug maker, cut full-year revenue forecasts because generics could cut into sales of its anti-arthritis drug, Celebrex. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Nigeria Ups Ebola Stakes on 1st Death

Nigeria Ups Ebola Stakes on 1st Death

Reuters - Business Video Online (July 29, 2014) — Nigerian authorities have shut and quarantined a Lagos hospital where a Liberian man died of the Ebola virus, the first recorded case of the highly-infectious disease in Africa's most populous economy. David Pollard reports Video provided by Reuters
Powered by NewsLook.com
Running 5 Minutes A Day Might Add Years To Your Life

Running 5 Minutes A Day Might Add Years To Your Life

Newsy (July 29, 2014) — According to a new study, just five minutes of running or jogging a day could add years to your life. Video provided by Newsy
Powered by NewsLook.com
Ebola Outbreak Poses Little Threat To U.S.: CDC

Ebola Outbreak Poses Little Threat To U.S.: CDC

Newsy (July 29, 2014) — The Ebola outbreak in West Africa poses little threat to Americans, according to officials with the Centers for Disease Control and Prevention. 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