Found the gene that produces the heart rate and heart rate monitors
The protein encoded by the gene HCN4, an ion channel membrane, causes the heart rate and is essential for survival.
The research published by the group of Dario DiFrancesco, director of PaceLab, Laboratory of Molecular Physiology and Neurobiology, University of Milan, in the journal Proceedings of the National Academy of Sciences USA, demonstrates for the first time that the heartbeat is regulated in order directed by a particular protein encoded by the gene HCN4, which acts as a channel or ion channel called “funny” or channel “pacemaker.” The presence of channels “funny” autoritmiche cardiac cells is essential for the generation of spontaneous activity and modulation frequency.
The laboratory has been operating for decades DiFrancesco in the field of experimental research and more specifically cardiac pacemaker in the study of the heart. These studies are based on the discovery channel “funny” made of DiFrancesco in the late ’70s.
Many previous studies of laboratory DiFrancesco have highlighted the link between the channels “funny” and the rhythmic activity of the heart.
For example in 2006 was detected in an Italian family, a mutation in the channel “funny” that causes a form of asymptomatic sinus bradycardia (Milanesi et al., 2006). In addition, a molecule that specifically blocks the function of these channels (ivabradine) is now marketed as a drug that induces the specific slowing of heart rate without side effects, this drug is now used in the treatment of angina pectoris.
However, direct evidence of the role of channels “funny” in controlling the rhythm and repetition was not yet available. The study published in PNAS now shows a direct function of these channel proteins. The study is based on the generation of genetically modified mice in which the deactivation of HCN4 gene leads to a decrease in heart rate. The slowing of the heart is proportional to the quantity of protein-channel removed from the cell membrane. The work shows that the channel “funny” directly controls the heart rate, and is essential for survival.
The study opens up prospects for obvious clinical interest. The heart rate monitor is a fundamental aspect of various antiarrhythmic therapies. The demonstration that the channels “funny” are the determinants of cardiac pacemaker implies the possibility of intervening on the mechanism of chronotropic control without harmful side effects.
