Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UBC researchers illuminate link between sodium, calcium and heartbeat using Canadian Light Source

14.02.2012
That flutter in your heart may have more to do with the movement of sodium ions than the glance of a certain someone across a crowded room.

Using the Canadian Light Source synchrotron, researchers from the University of British Columbia have revealed, for the first time, one of the molecular mechanisms that regulates the beating of heart cells by controlling the movement of sodium in out of the cells – and what calcium has to do with it.

The findings, published February 14 in the Proceedings of the National Academy of Sciences, sheds new light on this crucial physiological process while revealing the root cause and possible treatment targets of two potentially life-threatening cardiac arrhythmia conditions.

The contraction and relaxation of heart muscle cells depend on minute but finely regulated electrical impulses that are created when charged atoms – or ions – of metals such as sodium, potassium and calcium pass through complex molecular channels inside and between cells. Irregular heartbeats, referred to medically as arrhythmias, can happen when these channels leak or otherwise malfunction. Professors Filip van Petegem and Christopher Ahern, members of UBC's Cardiovascular Research Group, used the CLS to determine the molecular structure of a part of the channel that controls the flow of sodium to cells in the heart, as well as in other electrically-excitable cells such as in the nervous system.

"The heart is an electrical organ that depends on precise electrical signals to contract [and pump blood]" explains van Petegem. "It is crucial for heart rate that the signalling, controlled by the movement of sodium, be exact. So the entry of sodium into the cell is tightly regulated."

The sodium channel that passes through the outer membrane of heart cells is actually a huge, intertwined four-part molecule. The teams of Van Petegem and Ahern chose a section of the molecule that appeared to regulate the closing of the channel by forming a plug, thus stopping sodium from getting through.

The researchers were surprised to discover that a protein called calmodulin binds to the sodium channel, keeping it open by preventing the plug from forming. Calcium ions, in turn, regulate the connection between the protein and the channel: calcium ions cause the protein to hook up to the channel, keeping it open and letting sodium through.

Problems occur with the system when genetic mutations change the shape of the channel at the site where the protein binds, affecting how well the channel can open and close. The result – the flow of sodium into the muscle cells is disrupted and the heart does not beat regularly.

The scientists have been able to identify mutations in the site that lead to two different kinds of heart arrhythmia: Brugada Syndrome and Long Q-T type 3, so-called from the tell-tale trace doctors see on the ECG of patients suffering from the problem. Brugada syndrome is considered to be caused by not enough sodium getting into cells, while long Q-T is the result of too much sodium.

The results of the study could pave the way for the development of new drugs that can shore up how the calmodulin protein binds to the sodium channel, effectively treating both conditions as well as other arrhythmias.

"It's really a very elegant mechanism," notes van Petegem. "Many channels are regulated by calmodulin but not in such a simple way."

About the Canadian Light Source: The Canadian Light Source is Canada's national centre for synchrotron research and is a global leader and a recognized centre of excellence in synchrotron science and its applications. Located on the University of Saskatchewan campus in Saskatoon, the CLS has hosted over 4,600 user visits from academic institutions, government, and industry, and delivered over 15,000 experimental shifts to users from across Canada and 18 countries since 2005. CLS operations are funded by Western Economic Diversification Canada, Natural Sciences and Engineering Research Council, National Research Council of Canada, Canadian Institutes of Health Research, the Government of Saskatchewan and the University of Saskatchewan.

Matthew Dalzell | EurekAlert!
Further information:
http://www.lightsource.ca
http://www.lightsource.ca/media/quickfacts.php

More articles from Medical Engineering:

nachricht Virtual Reality in Medicine: New Opportunities for Diagnostics and Surgical Planning
07.12.2016 | Universität Basel

nachricht 3-D printed kidney phantoms aid nuclear medicine dosing calibration
06.12.2016 | Society of Nuclear Medicine

All articles from Medical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>