‘Popeye’ proteins help the heart adapt to stress

Medical Xpress) — 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.

Medical Research: February 24, 2012.

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. Read More