Navigation Links
Researchers identify new target for common heart condition
Date:1/8/2013

Researchers have found new evidence that metabolic stress can increase the onset of atrial arrhythmias, such as atrial fibrillation (AF), a common heart condition that causes an irregular and often abnormally fast heart rate. The findings may pave the way for the development of new therapies for the condition which can be expected to affect almost one in four of the UK population at some point in their lifetime.

The British Heart Foundation (BHF) study, led by University of Bristol scientists and published in Circulation: Arrhythmia and Electrophysiology, found that metabolic stress a condition induced by insufficient oxygen supply to the heart (e.g. following blockage of a coronary artery) caused marked changes in the electrical activity of the heart's atria (the upper chambers of the heart).

While it has been recognised for many years that metabolic stress causes ventricular arrhythmias abnormal heart rhythms that originate in the two lower chambers of the heart (the ventricles) and which form the basis to heart attacks it is the first time it has been demonstrated for arrhythmias in the atria.

The research team led by Dr Andrew James from the University's School of Physiology and Pharmacology together with Professor Saadeh Suleiman in the School of Clinical Sciences, examined the contribution of a particular kind of protein underlying the electrical activity of the atria during metabolic stress.

These proteins, known as KATP channels enable cells to respond to changes in metabolism. ATP (adenosine triphosphate) is a small molecule that represents the 'energy currency' for cell metabolism and when ATP levels inside cells fall, KATP channels are activated. For example, KATP channels in the pancreas are involved in the regulation of insulin secretion and drugs targeting these channels are used to treat type 2 diabetes mellitus.

Dr Andrew James, the study's lead author, said: "It is well-established that KATP channels in the ventricles of the heart can become activated following metabolic stress caused by blockage of a coronary artery. In principle, their activation could protect the heart muscle cells against metabolic stress-induced damage. On the other hand, the activation of ventricular KATP channels can contribute to disturbances in the electrical activity of the heart known as arrhythmias.

"Arrhythmias in the ventricles can be very dangerous, leading to ventricular fibrillation and death. Atrial arrhythmias, such as atrial fibrillation (AF), are not usually immediately fatal but they are very common and a major cause of stroke. Notably, KATP channels are also found in the atria but, in contrast to the ventricles, their role in atrial arrhythmias remains unknown."

The findings show that metabolic stress caused marked changes in the electrical activity of the atrium consistent with the activation of KATP channels. Electrical stimulation was applied to try to evoke atrial arrhythmia. It was possible to induce atrial arrhythmia during, but not before, metabolic stress.

Importantly, blockade of KATP channels with drugs used to treat patients with type 2 diabetes (glibenclamide and tolbutamide), completely reversed the effects of metabolic stress on the electrical activity of the atrium and prevented the induction of atrial arrhythmia. The anti-diabetic drugs were without effect in the absence of metabolic stress.

The findings represent a 'proof-of-principle' (the stage at which any new drug must undergo before full-scale clinical trials can begin) that atrial KATP channels can be activated by metabolic stress and facilitate atrial arrhythmias. Thus, atrial KATP channels may represent a target for drugs for the treatment of atrial arrhythmias, such as atrial fibrillation.

However, Dr James added: "Further studies are required and a key point to address will be whether differences exist between the properties of atrial, ventricular and pancreatic KATP channels that might be exploited to produce an atrial-selective drug. Perhaps these channels might be useful as targets to treat atrial arrhythmias."

Professor Jeremy Pearson, Associate Medical Director at the BHF, commented: "Atrial fibrillation is a very common irregular heart rhythm which greatly increases the risk of stroke. This study brings us closer to understanding how it develops, in particular in people whose hearts are under greater pressure due to the effects of a previous history of heart disease. It's vital that we continue to improve our understanding of this condition so we can find new treatments for patients in the future."


'/>"/>

Contact: Caroline Clancy
caroline.clancy@bristol.ac.uk
44-011-792-88086
University of Bristol
Source:Eurekalert

Related medicine news :

1. NIH awards $20 million over 5 years to train next generation of global health researchers
2. Researchers develop a new cell and animal model of inflammatory breast cancer
3. Researchers uncover a viable way for colorectal cancer patients to overcome drug resistance
4. Researchers Find Gene Mutations That May Be a Key to Autism
5. Researchers find evidence of banned antibiotics in poultry products
6. NJ stroke researchers report advances in spatial neglect research at AAN Conference
7. Autism by the numbers: Yale researchers examine impact of new diagnostic criteria
8. Researchers Map Brain Regions Linked to Intelligence
9. Researchers ID Genes That May Determine Mental Illness
10. Researchers Develop Blood Test for Depression
11. University of Cincinnati researchers win $3.7M grant from US Department of Defense
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/26/2016)... ... June 26, 2016 , ... PawPaws brand pet supplements owned ... developed to enhance the health of felines. The formula is all-natural and is made ... in the PawPaws Cat Kidney Support Supplement Soft Chews are Astragalus Root ...
(Date:6/25/2016)... (PRWEB) , ... June 25, 2016 , ... The temporary closing of Bruton Memorial Library ... City Observer , brings up a new, often overlooked aspect of head lice: the parasite’s ... for fumigation is not a common occurrence, but a necessary one in the event that ...
(Date:6/25/2016)... (PRWEB) , ... June 25, 2016 , ... On Friday, ... presented a Bronze Wellness at Work award to iHire in recognition of their exemplary ... part of the 7th annual Maryland Workplace Health & Wellness Symposium at the BWI ...
(Date:6/24/2016)... CA (PRWEB) , ... June 24, 2016 , ... Marcy was in a crisis. Her ... would lash out at his family verbally and physically. , “When something upset him, he ... he would use it. He would throw rocks at my other children and say he ...
(Date:6/24/2016)... NY (PRWEB) , ... June 24, 2016 , ... Topical BioMedics, Inc, makers of Topricin ... companies that call for a minimum wage raise to $12 an hour by 2020 and ... This will restore the lost value of the minimum wage, assure the wage floor does ...
Breaking Medicine News(10 mins):
(Date:6/24/2016)... 24, 2016 The Academy of Managed Care ... that would allow biopharmaceutical companies to more easily ... make formulary and coverage decisions, a move that addresses ... medicines. The recommendations address restrictions in the ... the drug label, a prohibition that hinders decision makers ...
(Date:6/24/2016)... -- According to a new market research ... Safety Pen Needles), Needle Length (4mm, 5mm, 6mm, 8mm, ... Purchase (Retail, Non-Retail) - Trends & Global Forecasts to ... for the forecast period of 2016 to 2021. This ... 2021 from USD 1.65 Billion in 2016, growing at ...
(Date:6/23/2016)... -- MedSource announced today that it has selected Datatrial,s ... choice.  This latest decision demonstrates MedSource,s commitment to ... by offering a state-of-the-art electronic data capture (EDC) ... the EDC platform of choice in exchange for ... long been a preferred EDC platform by our ...
Breaking Medicine Technology: