To date, the mechanisms underlying the maintenance of cardiac function at low body temperatures are poorly understood. Now, scientists at the Research Institute of Wildlife Ecology at the University of Veterinary Medicine, Vienna, together with colleagues at the University of Groningen in the Netherlands, have found that certain omega-3 and omega-6 fatty acids regulate the cardiac function and hence hibernation. These fatty acids control the process of maintaining a regular heartbeat, achieving lower body temperatures during hibernation and thereby ensuring the hibernator's survival.
Fatty acids regulate hibernation
In the present study Sylvain Giroud and colleagues were able to demonstrate that a specific omega-6 fatty acid, Linoleic acid (LA), regulates cardiac function and ensures a regular heartbeat during hibernation. The scientists found that hibernators show higher levels of LA in their heart tissue compared to animals in a non-hibernating state. The scientists determined the cardiac fatty acid composition of hibernating and non-hibernating Syrian hamsters (Mesocricetus auratus). They found that hamsters had higher LA levels during the cooling phase and in deep hibernation than during the active period. Additionally, the researchers investigated a specific omega-3 fatty acid, Docosahexaenoic Acid (DHA), which was significantly lower in the examined animals during hibernation. The scientists concluded that both high levels of LA and low levels of DHA are essential for hibernation. According to the study, the amounts of these specific omega-6 and -3 fatty acids in the heart can be regulated up and down, depending on the season. In summer, unlike during hibernation, high levels of DHA protect the heart from overexertion.
Activity of calcium pump in the heart
Certain fatty acids can influence the activity of so-called calcium pumps. These pumps are responsible for proper muscle contractions in the bo
|Contact: Sylvain Giroud|
University of Veterinary Medicine -- Vienna