Navigation Links
Mitochondrial dysfunction and redox signaling in atrial tachyarrhythmia
Date:4/23/2008

Researchers at the University Hospital of Magdeburg (Germany) have discovered that atrial tachycardia is associated with mitochondrial dysfunction and oxidative stress followed by the activation of the NF-kB signalling pathway with induction of NF-kB target gene expression in atrial tissue. Their study will appear in the May 08 issue of Experimental Biology and Medicine. Multiple tachycardia-associated factors appear to contribute to this response, which all are directly or indirectly linked to oxidative stress. Accordingly, blockade of the angiotensin II type 1 receptor, inhibition of L-type calcium channels, inhibition of NADPH oxidase, applications of antioxidants, and inhibition of NF-B activation were all found to abolish or decrease the tachycardia-dependent changes in the atrial tissue.

The interdisciplinary research team, led by Uwe Lendeckel, a professor of Experimental Internal Medicine and Andreas Goette, Deputy Chief of Cardiology, designed the study to determine the influence of tachyarrhythmia on endocardial dysfunction (called endocardial remodelling) and to decipher the molecular mechanism(s) that translate pathologically increased heart rates into myocardial/endocardial dysfunction. Endocardial dysfunction appears as a well recognised risk factor for thromboembolic events in patients with atrial fibrillation (AF). Therefore, the underlying pathophysiology of endocardial remodelling is of clinical importance.

The facts that equal results were observed in ex vivo atrial tissue from patients with AF and in ex vivo rapidly paced tissue samples from patients with sinus rhythm (SR), together with the observation that verapamil most potently prevented oxidative stress and associated signalling pathway activation, led us to conclude that the elevated frequency per se and concomitant Ca2+-overload precede and induce mitochondrial dysfunction and oxidative stress in AF said Lendeckel. Goette added Our results have several clinical implications. Atrial ischemia produces an increase in cellular calcium load and oxidative stress in the atria. Thereby, atrial ischemia provides a specific substrate for AF. Recent experimental and clinical data showed that calcium channel blockers have a specific efficacy to prevent AF in this specific situation. Thus, our data provide more information about the potential pathophysiologic mechanism explaining why calcium channel blockers are effective and useful to attenuate atrial cellular remodelling especially under conditions of increased cellular calcium load and oxidative stress. The authors say the use of ex vivo human atrial tissue from patients with and without AF as well as the rapid pacing of atrial tissue slices to mimic AF ex vivo is a valuable approach to identify molecular and cellular effects that are solely due to the AF excluding the effects of concomitant cardiac diseases.

Dr. Steven R. Goodman, Editor-in-Chief of Experimental Biology and Medicine said Professor Lendeckel, Professor Goette and colleagues have demonstrated that inward calcium current via L-type calcium channels contributes to oxidative stress and increased expression of oxidative stress markers and adhesion molecules during cardiac tachyarrhythmia.. He further stated These observations are important to the understanding of the molecular mechanisms by which calcium overload and resulting mitochondrial dysfunction and resulting oxidative stress impact atrial remodelling during atrial fibrillation.


'/>"/>

Contact: Dr. Uwe Lendeckel
uwe.lendeckel@med.ovgu.de
49-391-671-4454
Society for Experimental Biology and Medicine
Source:Eurekalert

Related biology news :

1. Zebrafish to shed light on human mitochondrial diseases
2. Scientists show that mitochondrial DNA variants are linked to risk factors for type 2 diabetes
3. Study uncovers clues to cystic fibrosis gene dysfunction and gastrointestinal disease
4. Chloroplast f and m Thioredoxins Discovered in Nonphotosynthetic Tissues
5. Science expands Science Signaling, featuring research related to medical advances, and more
6. Newly defined signaling pathway could mean better biofuel sources
7. Rong Li Lab reports protein interactions of MAP kinase signaling pathway
8. Study finds blocking angiogenesis signaling from inside cell may lead to serious health problems
9. Scientists find clue to mechanisms of gene signaling and regulation
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/27/2017)... ROCKVILLE CENTRE, N.Y. , March 27, 2017 ... by Healthcare Information and Management Systems Society (HIMSS) ... Analytics Outpatient EMR Adoption Model sm . In ... top 12% of U.S. hospitals using an electronic ... recognized CHS for its high level of EMR ...
(Date:3/23/2017)... 23, 2017 The report "Gesture Recognition and Touchless Sensing ... Geography - Global Forecast to 2022", published by MarketsandMarkets, the market is expected ... 29.63% between 2017 and 2022. Continue Reading ... ... ...
(Date:3/22/2017)... March 21, 2017 Optimove , ... by retailers such as 1-800-Flowers and AdoreMe, today ... Recommendations and Replenishment. Using Optimove,s machine learning algorithms, ... product and replenishment recommendations to their customers based ... predictions of customer intent drawn from a complex ...
Breaking Biology News(10 mins):
(Date:8/16/2017)... , Aug. 16, 2017  Kingfisher Talent, the ... development, and Virdis Group, global executive search specialists in the ... enables clients to leverage the expertise and reach of both ... here in the Boston biotech hub, ... leadership talent throughout the US, Canada ...
(Date:8/15/2017)... , ... August 15, 2017 , ... ... biosensors that accelerate pharmaceutical and biotherapeutics development, announces the launch of the new ... steps needed to gain kinetic binding data for a wide range of molecules, ...
(Date:8/15/2017)... , ... August 15, 2017 , ... ... family of 6” modular downlights designed to stay tightly sealed and perform efficiently ... where damp and wet location listings just aren't enough, such as: hospitals; behavioral ...
(Date:8/15/2017)... ... 15, 2017 , ... JULABO USA introduces its new website ... makes it easy to navigate through the site whether you’re in the office, ... information, educational industry content and visit the company’s social media accounts, all on ...
Breaking Biology Technology: