Featured Research

from universities, journals, and other organizations

Novel role found for calcium channels in pacemaker cell function

Date:
March 10, 2011
Source:
American Institute of Physics
Summary:
Pacemaker cells in the sinoatrial node control heart rate, but what controls the ticking of these pacemaker cells? New research reveals, for the first time, a critical functional interaction between Cav1.3 calcium ion (Ca2+) channels and ryanodine-receptor (RyR) mediated Ca2+ signaling.

A mouse pacemaker cell initiates local Ca2+ releases in the diastolic phase. Red spots are the regions with maximal [Ca2+]i released.
Credit: Image courtesy of A. Torrente/CNRS France 2011

Pacemaker cells in the sinoatrial node control heart rate, but what controls the ticking of these pacemaker cells? New research by Angelo Torrente and his colleagues of the M.E. Mangoni group's, reveals, for the first time, a critical functional interaction between Cav1.3 calcium ion (Ca2+) channels and ryanodine-receptor (RyR) mediated Ca2+ signaling.

The study also sheds light on a long-standing debate regarding the relative contributions of the 'funny current' generated by ion channels and the RyR dependent spontaneous diastolic Ca2+ release theory in determining heart rate.

The investigation by the research team compared pacemaker cells in normal mice with mutants that lacked the L-type Cav1.3 channels to contrast how they handled calcium. They found that the absence of Cav1.3 channels in sinoatrial node (SAN) cells reduced the frequency of Ca2+ transients, which determine the rate of cardiac muscle contraction. The Cav1.3 channels were also found to be important regulators of ryanodine-receptor dependent local calcium release in the diastolic pacemaker phase. Overall, their results show that local calcium release in SAN cells is tightly controlled by the Cav1.3 channels.

Defects in calcium channels controlling heart muscle function are known to cause heart failure, and this study reveals that Cav1.3 mutant mice also suffer from bradycardia and other cardiac arrhythmias.

"Our results clarify the role of Cav1.3 channels in pacemaker generation, and are a step towards using it as a target for drug therapy to treat heart dysfunction related to the sinoatrial node," says A. Torrente of CNRS in Montpellier, France, who was the lead author on the study.

Not only Cav1.3 channels are critical to the heart pacemaker cell function, they appear to be important to several other cellular mechanisms as well. In both humans and mice, Cav1.3 mutations have been linked to sinoatrial node dysfunction and deafness (or SANDD) syndrome. Cav1.3 channels are believed to play a role in pancreatic β-cell stimulation, and they may also serve as pacemaker channels in the central nervous system, playing a pathophysiological role in Parkinson's disease.

"A better understanding of these channels in SAN could help us to comprehend the mechanism of calcium release in many other tissues and disease conditions as well," says Torrente.


Story Source:

The above story is based on materials provided by American Institute of Physics. Note: Materials may be edited for content and length.


Cite This Page:

American Institute of Physics. "Novel role found for calcium channels in pacemaker cell function." ScienceDaily. ScienceDaily, 10 March 2011. <www.sciencedaily.com/releases/2011/03/110309112856.htm>.
American Institute of Physics. (2011, March 10). Novel role found for calcium channels in pacemaker cell function. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2011/03/110309112856.htm
American Institute of Physics. "Novel role found for calcium channels in pacemaker cell function." ScienceDaily. www.sciencedaily.com/releases/2011/03/110309112856.htm (accessed July 23, 2014).

Share This




More Health & Medicine News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

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
Thousands Who Can't Afford Medical Care Flock to Free US Clinic

Thousands Who Can't Afford Medical Care Flock to Free US Clinic

AFP (July 23, 2014) America may be the world’s richest country, but in terms of healthcare, the World Health Organisation ranks it 37th. Thousands turned out for a free clinic run by "Remote Area Medical" with a visit from the Governor of Virginia. Duration: 2:40 Video provided by AFP
Powered by NewsLook.com
Stone Fruit Listeria Scare Causes Sweeping Recall

Stone Fruit Listeria Scare Causes Sweeping Recall

Newsy (July 22, 2014) The Wawona Packing Company has issued a voluntary recall on the stone fruit it distributes due to a possible Listeria outbreak. Video provided by Newsy
Powered by NewsLook.com
Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Newsy (July 22, 2014) The 83 new genetic markers could open dozens of new avenues for schizophrenia treatment research. 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