Biological pacemaker

Source: Wikipedia, the free encyclopedia.

A biological pacemaker is one or more types of cellular components that, when "implanted or injected into certain regions of the heart," produce specific electrical stimuli that mimic that of the body's natural pacemaker cells.[1] Biological pacemakers are indicated for issues such as heart block, slow heart rate, and asynchronous heart ventricle contractions.[2][3]

The biological pacemaker is intended as an alternative to the

battery exchange, and venous thrombosis. The need for an alternative is most obvious in children, including premature newborn babies, where size mismatch and the fact that pacemaker leads do not grow with children are a problem.[1] A more biological approach has been taken in order to mitigate many of these issues. However, the implanted biological pacemaker cells still typically need to be supplemented with an artificial pacemaker while the cells form the necessary electrical connections with cardiac tissue.[1]

History

The first successful experiment with biological pacemakers was carried out by

inward-rectifier potassium current Ik1 encoded by the gene Kir2 which is not expressed in pacemaker cells
. By specific inhibition of Ik1 below a certain level, spontaneous activity of cardiomyocytes was observed with resemblance to the action potential pattern of genuine pacemaker cells.

Meanwhile, other genes and cells have been discovered, including heart muscle cells derived from

myocytes.[6] In 2010, Ruhparwar's group again demonstrated a type of biological pacemaker, this time showing that by injection of the "Adenylate Cyclase" gene into the heart muscle a biological cardiac pacemaker can be created.[7]

In 2014, a gene called TBX18 has been non-invasively applied to speed up heart rates caused by heart block.[2] More recent studies in 2015, has been experimented optogenetic approach in the rats heart, where a light sensitive transgene (Channelrhodopsin-2) injected to several sites of rat's ventricular, which, furthermore, can simultaneously stimulate the injection sites by a blue light irradiation.[3]

References

  1. ^ . Retrieved 18 February 2016.
  2. ^ a b Ellis, Marie (17 July 2014). "Scientists create 'biological pacemakers' by transplanting gene into hearts". Medical News Today. MediLexicon International Ltd. Retrieved 18 February 2016.
  3. ^ a b Hattori, K. (22 June 2015). "Blue light sets the beat in biological pacemaker". Science Daily. Retrieved 18 February 2016.
  4. PMID 12062274
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