Menu
23/02/2012
'Popeye' Proteins Help The Heart Adapt To Stress
A family of proteins named after Popeye play an essential role in allowing the heart to respond to stress, according to a study published today in the Journal of Clinical Investigation. The finding could help scientists develop new treatments for abnormal heart rhythms.
Popeye domain containing proteins (Popdc for short) were discovered 10 years ago and named because they are found in abundance in muscles, but until now their function has been unclear. The new study reveals that they help the heart to increase its rhythm in response to the hormone adrenaline, which is released in times of mental or physical stress.
Scientists at Imperial College London, the University of Birmingham, and the University of Würzburg in Germany studied mice that were deficient in Popdc proteins.
In healthy people and mice, the heart's natural pacemaker responds to adrenaline by making the heart beat faster in order to deliver more oxygen around the body. But in the mice that lacked Popdc, the heart rate slowed when they were put in stressful situations.
Many elderly people's heart rates slow down in a similar way in response to stress. These people may be diagnosed with a condition called sick sinus syndrome, which normally means they need to have an artificial pacemaker fitted. The researchers anticipate that the findings might lead to new treatments for this and other heart rhythm disorders that can be triggered by stress, such as arrhythmias, atrial fibrillation and sudden cardiac death.
Professor Thomas Brand, from the National Heart and Lung Institute at Imperial College London, who led the study, said: "Many elderly people have problems with the natural pacemaker in their heart that can be triggered by stress, but we still know little about the exact mechanics of the heart's response. These findings show that in mice, Popdc proteins have an important function in regulating the heart's rhythm and it is reasonable to deduce that the same is true in humans. Mice with mutations in the genes for these proteins have the same abnormal stress responses as some elderly people do.
"Studying these mice further will give us more clues about what goes wrong in the heart's pacemaker, and might help us develop new drugs for heart rhythm disorders. We also plan to look at the Popdc genes in people with sick sinus syndrome, to see whether mutations there might be connected to the condition."
Popdc is located in the outer membrane of the heart's specialised pacemaker cells. The researchers found that Popdc interacts with a signalling molecule triggered by adrenaline, known as cAMP, and that this changes the electrical properties of the cell membrane. They think that this might be the mechanism by which adrenaline influences the heart's rhythm.
"During exercise, the heartbeat can increase by three times over its resting rate, enabling the muscles to work harder," Professor Brand said. "This is mainly brought about by adrenaline, but how adrenaline acts on the heart's cells is not fully understood. This study helps us understand the mechanism by which the heart adapts to stress."
The research was funded by Deutsche Forschungsgemeinschaft, the Interdisciplinary Center for Clinical Research, and Fondation Leducq.
(GK)
Popeye domain containing proteins (Popdc for short) were discovered 10 years ago and named because they are found in abundance in muscles, but until now their function has been unclear. The new study reveals that they help the heart to increase its rhythm in response to the hormone adrenaline, which is released in times of mental or physical stress.
Scientists at Imperial College London, the University of Birmingham, and the University of Würzburg in Germany studied mice that were deficient in Popdc proteins.
In healthy people and mice, the heart's natural pacemaker responds to adrenaline by making the heart beat faster in order to deliver more oxygen around the body. But in the mice that lacked Popdc, the heart rate slowed when they were put in stressful situations.
Many elderly people's heart rates slow down in a similar way in response to stress. These people may be diagnosed with a condition called sick sinus syndrome, which normally means they need to have an artificial pacemaker fitted. The researchers anticipate that the findings might lead to new treatments for this and other heart rhythm disorders that can be triggered by stress, such as arrhythmias, atrial fibrillation and sudden cardiac death.
Professor Thomas Brand, from the National Heart and Lung Institute at Imperial College London, who led the study, said: "Many elderly people have problems with the natural pacemaker in their heart that can be triggered by stress, but we still know little about the exact mechanics of the heart's response. These findings show that in mice, Popdc proteins have an important function in regulating the heart's rhythm and it is reasonable to deduce that the same is true in humans. Mice with mutations in the genes for these proteins have the same abnormal stress responses as some elderly people do.
"Studying these mice further will give us more clues about what goes wrong in the heart's pacemaker, and might help us develop new drugs for heart rhythm disorders. We also plan to look at the Popdc genes in people with sick sinus syndrome, to see whether mutations there might be connected to the condition."
Popdc is located in the outer membrane of the heart's specialised pacemaker cells. The researchers found that Popdc interacts with a signalling molecule triggered by adrenaline, known as cAMP, and that this changes the electrical properties of the cell membrane. They think that this might be the mechanism by which adrenaline influences the heart's rhythm.
"During exercise, the heartbeat can increase by three times over its resting rate, enabling the muscles to work harder," Professor Brand said. "This is mainly brought about by adrenaline, but how adrenaline acts on the heart's cells is not fully understood. This study helps us understand the mechanism by which the heart adapts to stress."
The research was funded by Deutsche Forschungsgemeinschaft, the Interdisciplinary Center for Clinical Research, and Fondation Leducq.
(GK)
Related UK National News Stories
Click here for the latest headlines.
09 April 2015
Shorter People More At Risk Of Heart Disease
Shorter people are more at risk of coronary heart disease, according to a new study led by Professor Sir Nilesh Samani, British Heart Foundation Professor of Cardiology and Head of the Department of Cardiovascular Sciences. The research discovered that every 2.5 inches of change in height affects the risk of coronary heart disease by 13.5%.
Shorter People More At Risk Of Heart Disease
Shorter people are more at risk of coronary heart disease, according to a new study led by Professor Sir Nilesh Samani, British Heart Foundation Professor of Cardiology and Head of the Department of Cardiovascular Sciences. The research discovered that every 2.5 inches of change in height affects the risk of coronary heart disease by 13.5%.
20 April 2010
97% Unaware Of 'Muffin Top' Health Risks
Most people have no idea that rolls of fat around their waistline are putting them at increased risk of heart disease, diabetes and cancer, a poll reveals. While being overweight or obese in general poses a health hazard, concentrated fat deposits around the midriff – commonly nicknamed spare tyres or muffin tops – are particularly dangerous.
97% Unaware Of 'Muffin Top' Health Risks
Most people have no idea that rolls of fat around their waistline are putting them at increased risk of heart disease, diabetes and cancer, a poll reveals. While being overweight or obese in general poses a health hazard, concentrated fat deposits around the midriff – commonly nicknamed spare tyres or muffin tops – are particularly dangerous.
17 October 2008
Aspirin 'Doesn't Prevent Heart Attacks'
Despite GPs prescribing the drugs to many thousands of their patients by way of prevention, new research suggests that aspirin does not after all prevent heart attacks.
Aspirin 'Doesn't Prevent Heart Attacks'
Despite GPs prescribing the drugs to many thousands of their patients by way of prevention, new research suggests that aspirin does not after all prevent heart attacks.
29 May 2009
Widespread Use Of Aspirin Slammed
A new study in The Lancet medical journal has found that healthy people who take aspirin reduced their already small risk of heart attack or stroke by just 12%. However, the small risk of internal bleeding increased by a third.
Widespread Use Of Aspirin Slammed
A new study in The Lancet medical journal has found that healthy people who take aspirin reduced their already small risk of heart attack or stroke by just 12%. However, the small risk of internal bleeding increased by a third.
02 April 2012
Heart Failure's Effects Can Be Reversed With Rest
Structural changes in heart muscle cells after heart failure can be reversed by allowing the heart to rest, according to research at Imperial College London. Findings from a study in rats published today in the European Journal of Heart Failure show that the condition's effects on heart muscle cells are not permanent, as has generally been thought.
Heart Failure's Effects Can Be Reversed With Rest
Structural changes in heart muscle cells after heart failure can be reversed by allowing the heart to rest, according to research at Imperial College London. Findings from a study in rats published today in the European Journal of Heart Failure show that the condition's effects on heart muscle cells are not permanent, as has generally been thought.
-
Northern Ireland WeatherToday:A showery start with outbreaks most frequent north of Lough Neagh and through the morning, before dwindling during the afternoon as the northwest breezes ease and brighter spells of weak sunshine prosper. Maximum temperature 8 °C.Tonight:A dry night, save for a few light showers around the coasts, with prolonged clear spells and light winds bringing a frosty dawn for many in central and southern parts. Minimum temperature -3 °C.
