How much calcium could a hibernating woodchuck's heart cells sequester, if a hibernating woodchuck's heart cells could sequester calcium? More than enough, it turns out, to protect the animals from cardiac arrhythmias – abnormal heart rhythms such as ventricular tachycardia and ventricular fibrillation that can lead to sudden cardiac death – according to a new study of the hibernating animals that may provide insight into arrhythmia therapies. The findings will be presented at a poster session at the 56th Annual Meeting of the Biophysical Society (BPS), which will take place Feb. 25-29 in San Diego, Calif.
Bear and bats can be roused from their slumber by external stimuli. But woodchucks (Marmota monax), also known as groundhogs, are "true hibernators," which means they can enter a profoundly altered physiological state: their body temperature drops to near-ambient levels (often as low as freezing) and heart and respiration rates slow dramatically. Despite – or perhaps because of – these changes, hibernating animals have been found to be more resistant to cardiac arrhythmias and sudden cardiac death.
Electrophysiologist Lai-Hua Xie, an assistant professor at the University of Medicine and Dentistry of New Jersey (UMDNJ)-New Jersey Medical School in Newark, and his colleagues examined muscle cells, or myocytes, isolated in winter and in summer from woodchucks. Using a charge-coupled device (CCD) camera, the researchers monitored the release and uptake of calcium ions when the cells were activated. The team found that in winter woodchucks, the myocyte sarcoplasmic reticulum – the membrane system in muscle cells that stores and releases calcium – had less spontaneous leakage of calcium, released more of it during excitation, and took it back up faster than that of summer woodchucks or non-hibernating animals. This is likely, he says, "to generate a stronger contraction and faster relaxation, and most importantly, to prevent abnormal changes in the heart's electrical activities called afterdepolarizations."
The overall effect, Xie says, is a "higher resistance to arrhythmia in woodchucks in winter. Understanding these cardiac adaptive mechanisms in hibernators may suggest new strategies to protect non-hibernating animals, especially humans, from fatal cardiac arrhythmias induced by hypothermic stresses and myocardial ischemia."
Xie and his colleagues conducted the work with funding from the National Institutes of Health and in collaboration with Stephen Vatner, director of the UMDNJ-New Jersey Medical School Cardiovascular Research Center.
The presentation, "Calcium handling properties in a hibernating animal: Insights into antiarrhythmic mechanisms," is at 1:45 on Sunday, Feb. 26, 2012, in the San Diego Convention Center, Hall FGH. ABSTRACT: http://tinyurl.com/7mtrp4a
This news release was prepared for the Biophysical Society (BPS) by the American Institute of Physics (AIP).ABOUT THE 2012 ANNUAL MEETING
The 56th Annual Meeting will be held at the San Diego Convention Center (111 W. Harbor Drive, San Diego, CA 92101), located three miles from the San Diego International Airport and less than one mile from the Amtrak station. The San Diego Trolley has two stops directly in front of the Center at Harbor Drive/First Avenue and Harbor Drive/Fifth Avenue.QUICK LINKS
Housing and Travel Information: http://www.biophysics.org/2012meeting/AccommodationsTravel/HotelInformation/tabid/2479/Default.aspx
Program Abstracts and Itinerary Planner: http://www.abstractsonline.com/plan/start.aspx?mkey=%7B5B4BAD87%2D5B6D%2D4994%2D84CE%2DB3B13E2AEAA3%7DPRESS REGISTRATION
Ellen R. Weiss | EurekAlert!
Flow of cerebrospinal fluid regulates neural stem cell division
22.05.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
Chemists at FAU successfully demonstrate imine hydrogenation with inexpensive main group metal
22.05.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.
The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...
Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.
Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...
A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.
Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
18.05.2018 | Power and Electrical Engineering
18.05.2018 | Information Technology
18.05.2018 | Information Technology