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:3/28/2017)... , March 28, 2017 The ... Hardware (Camera, Monitors, Servers, Storage Devices), Software (Video Analytics, ... Region - Global Forecast to 2022", published by MarketsandMarkets, ... 2016 and is projected to reach USD 75.64 Billion ... and 2022. The base year considered for the study ...
(Date:3/23/2017)... 2017 Research and Markets has announced the ... Trends - Industry Forecast to 2025" report to their offering. ... The Global ... of around 8.8% over the next decade to reach approximately $14.21 ... market estimates and forecasts for all the given segments on global ...
(Date:3/20/2017)... PMD Healthcare announces the release of its ... System (WMS), a remote, real-time lung health monitoring and ... is a Medical Device, Digital Health, and Chronic Care ... innovative solutions that empower people to improve their healthcare ... developed the first ever personal spirometer, Spiro PD, which ...
Breaking Biology News(10 mins):
(Date:4/27/2017)... , April 27, 2017  Pendant Biosciences, Inc. ... innovative surface modification and drug delivery technologies, today announced ... Innovation, JLABS @ Toronto . ... Officer of Pendant Biosciences, noted, "We are excited to ... community, and are honored to be the ...
(Date:4/26/2017)... Myrtle Beach, SC (PRWEB) , ... April 26, ... ... for the mind, has teamed up with NASA to showcase the future of ... NASA’s Space Launch System (SLS) rocket and Orion spacecraft and includes a guest ...
(Date:4/26/2017)... ... April 26, 2017 , ... Baltimore ... Bioflash MailGuardtm mail security screening solution at the National Postal Forum 2017 in ... provides a fast, highly accurate, easy to use and low cost threat detection ...
(Date:4/26/2017)... 2017  Genisphere LLC, provider of the 3DNA ... collaborative and sponsored research agreement with the University ... The overall goal of the partnership is to ... designs and formulations after in vivo ... vasculature as well as inflammatory responses, demonstrating various ...
Breaking Biology Technology: