Read by QxMD icon Read

ROS and arrhythmias

Shogo Tanno, Kenshiro Yamamoto, Yasutaka Kurata, Maya Adachi, Yumiko Inoue, Naoyuki Otani, Mutsuo Mishima, Yasutaka Yamamoto, Masanari Kuwabara, Kazuhide Ogino, Junichiro Miake, Haruaki Ninomiya, Yasuaki Shirayoshi, Futoshi Okada, Kazuhiro Yamamoto, Ichiro Hisatome
BACKGROUND: Ischemia/reperfusion (I/R) injury triggers cardiac dysfunctions via creating reactive oxygen species (ROS). Because xanthine oxidase (XO) is one of the major enzymes that generate ROS, inhibition of XO is expected to suppress ROS-induced I/R injury. However, it remains unclear whether XO inhibition really yields cardioprotection during I/R. The protective effects of the XO inhibitors, topiroxostat and allopurinol, on cardiac I/R injury were evaluated.Methods and Results:Using isolated rat hearts, ventricular functions, occurrence of arrhythmias, XO activities and thiobarbituric acid reactive substances (TBARS) productions and myocardial levels of adenine nucleotides before and after I/R, and cardiomyocyte death markers during reperfusion, were evaluated...
February 28, 2018: Circulation Journal: Official Journal of the Japanese Circulation Society
Kenji Suita, Takayuki Fujita, Wenqian Cai, Yuko Hidaka, Huiling Jin, Rajesh Prajapati, Masanari Umemura, Utako Yokoyama, Motohiko Sato, Björn C Knollmann, Satoshi Okumura, Yoshihiro Ishikawa
Sympathetic activation causes clinically important arrhythmias including atrial fibrillation (AF) and ventricular tachyarrhythmia. Although the usefulness of β-adrenergic receptor blockade therapy is widely accepted, its multiple critical side effects often prevent its initiation or continuation. The aim of this study is to determine the advantages of vidarabine, an adenylyl cyclase (AC)-targeted anti-sympathetic agent, as an alternative treatment for arrhythmia. We found that vidarabine, which we identified as a cardiac AC inhibitor, consistently shortens AF duration and reduces the incidence of sympathetic activation-induced ventricular arrhythmias...
February 16, 2018: Pflügers Archiv: European Journal of Physiology
Julian Mustroph, Olivia Wagemann, Simon Lebek, Daniel Tarnowski, Jasmin Ackermann, Marzena Drzymalski, Steffen Pabel, Christof Schmid, Stefan Wagner, Samuel Sossalla, Lars S Maier, Stefan Neef
AIMS: Ethanol has acute negative inotropic and arrhythmogenic effects. The underlying mechanisms, however, are largely unknown. Sarcoplasmic reticulum Ca2+-leak is an important mechanism for reduced contractility and arrhythmias. Ca2+-leak can be induced by oxidative stress and Ca2+/Calmodulin-dependent protein kinase II (CaMKII). Therefore, we investigated the influence of acute ethanol exposure on excitation-contraction coupling in atrial and ventricular cardiomyocytes. METHODS AND RESULTS: Isolated human atrial and murine atrial or ventricular cardiomyocytes were preincubated for 30 min and then superfused with control solution or solution containing ethanol...
February 2, 2018: Journal of Molecular and Cellular Cardiology
Ibrahim El-Battrawy, Zhihan Zhao, Huan Lan, Jan-Dierk Schünemann, Katherine Sattler, Fanis Buljubasic, Bence Patocskai, Xin Li, Gökhan Yücel, Siegfried Lang, Daniel Nowak, Lukas Cyganek, Karen Bieback, Jochen Utikal, Wolfram-Hubertus Zimmermann, Ursula Ravens, Thomas Wieland, Martin Borggrefe, Xiao-Bo Zhou, Ibrahim Akin
BACKGROUND AND PURPOSE: Previous studies revealed that Takotsubo cardiomyopathy (TTC), a transient disorder of ventricular dysfunction affecting predominantly postmenopausal women, is associated with acquired long QT syndrome and arrhythmias, but the exact pathophysiologic mechanism is unknown. Our aim is to investigate the electrophysiological mechanism for QT-prolongation in TTC-patients by using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). METHODS: hiPSC-CMs, which were generated from human skin fibroblasts of three healthy donors, were treated by estradiol (10μM for one week) and a toxic concentration of isoprenaline (Iso, 1mM for 2h)...
March 1, 2018: International Journal of Cardiology
Samira Barangi, A Wallace Hayes, Gholamreza Karimi
Atrial fibrillation (AF) is the most common cardiac arrhythmia that occurs because of several different risk factors, e.g., valvular heart disease, coronary artery disease, age ≥75 years, hypertension and diabetes mellitus. One key risk factor that results in AF, is oxidative stress. Evidence suggests that there is a correlation between oxidative processes and the genesis of AF. Oxidative stress occurs when the generation of reactive oxygen species (ROS) increase due to excessive activity of enzymes including NADPH oxidase (NOX) and xanthine oxidase; or its degradation decrease by dysfunctional antioxidant enzyme systems, such as superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx)...
September 19, 2017: Critical Reviews in Food Science and Nutrition
Chunxia Yin, Yaoxu Chen, Huanlin Wu, Danping Xu, Wen Tan
Isosteviol has been demonstrated to play a protective role during ischemia reperfusion (I/R) myocardial infarction. However, the underlying electrophysiological mechanisms of isosteviol are still unknown. Our previous study showed that the rapid component of the delayed rectifier potassium channel (IKr) plays an important role in the prolongation of I/R-induced QT interval-related arrhythmia. This study aimed to investigate whether isosteviol could attenuate I/R-induced prolongation of the action potential duration (APD) along with inhibition of IKr, and we aimed to clarify the electrophysiological mechanism of isosteviol to determine its cardioprotective effects in guinea pigs...
December 2017: Biochimica et Biophysica Acta
Nami Kim, Youngae Jung, Miso Nam, Mi Sun Kang, Min Kyung Lee, Youngjin Cho, Eue-Keun Choi, Geum-Sook Hwang, Hyeon Soo Kim
Inflammation is a common cause of cardiac arrhythmia. Angiotensin ІІ (Ang ІІ) is a major contributing factor in the pathogenesis of cardiac inflammation; however, its underlying molecular mechanism remains unclear. Here, we explored the effect of Ang ІІ on inflammatory mechanisms and oxidative stress using HL-1 atrial myocytes. We showed that Ang ІІ activated c-Jun N-terminal kinase (JNK) phosphorylation and other inflammatory markers, such as transforming growth factor-β1 (TGF-β1) and tumor necrosis factor-α (TNF-α)...
September 4, 2017: Scientific Reports
Thomas Münzel, Giovanni G Camici, Christoph Maack, Nicole R Bonetti, Valentin Fuster, Jason C Kovacic
Vascular disease and heart failure impart an enormous burden in terms of global morbidity and mortality. Although there are many different causes of cardiac and vascular disease, most causes share an important pathological mechanism: oxidative stress. In the failing heart, oxidative stress occurs in the myocardium and correlates with left ventricular dysfunction. Reactive oxygen species (ROS) negatively affect myocardial calcium handling, cause arrhythmia, and contribute to cardiac remodeling by inducing hypertrophic signaling, apoptosis, and necrosis...
July 11, 2017: Journal of the American College of Cardiology
Yu-Lei Deng, Jun-Yan Zhao, Ji-Hua Yao, Qiang Tang, Le Zhang, Hong-Lian Zhou, Cun-Tai Zhang, Jia-Gao Lv, Xiao-Qing Quan
T-wave alternans (TWA) is a potent arrhythmia substrate under the conditions of acute myocardial ischemia. Abnormal intracellular calcium cycling contributes to the genesis of cardiac alternans. Ryanodine receptor (RyR) is a pivotal Ca(2+) cycling protein central to Ca(2+) signaling in the heart. Here, we investigated the potential role of RyR in cardiac alternans and ventricular arrhythmias in acute myocardial ischemia. Transmembrane action potentials were simultaneously recorded from epicardium and endocardium together with a transmural ECG and isometric contraction force in the arterially perfused left ventricular wedge preparations...
2017: American Journal of Translational Research
Yaoxu Chen, Chunxia Yin, Yingying Yang, Zhuo Fan, Jinling Shang, Wen Tan
Ischemia/reperfusion (I/R) induces prolongation of QT interval and action potential duration (APD), which is a major cardiac electrical disorder in patients with arrhythmias. However, the mechanism of QT interval prolongation induced by I/R remains unclear. In the present study, we hypothesized that the rapid component of delayed rectifier potassium (IKr) channel plays an important role in I/R-induced QT interval prolongation. We observed a marked attenuation of IKr and a significant prolongation of action potential duration (APD) in a simulated I/R system with sodium dithionite (Na2S2O4) in ventricular myocytes of guinea pigs...
July 2017: Journal of Electrocardiology
Sung Ryul Lee, Jin Han
Mitochondria individually encapsulate their own genome, unlike other cellular organelles. Mitochondrial DNA (mtDNA) is a circular, double-stranded, 16,569-base paired DNA containing 37 genes: 13 proteins of the mitochondrial respiratory chain, two ribosomal RNAs (rRNAs; 12S and 16S), and 22 transfer RNAs (tRNAs). The mtDNA is more vulnerable to oxidative modifications compared to nuclear DNA because of its proximity to ROS-producing sites, limited presence of DNA damage repair systems, and continuous replication in the cell...
2017: Advances in Experimental Medicine and Biology
Peiying Zhang
Pathological remodeling of the myocardium is an integral part of the events that lead to heart failure (HF), which involves altered gene expression, disturbed signaling pathways and altered Ca(2+) homeostasis and the players involved in this process. Of particular interest is the chronic activation of Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) isoforms in heart, which further aggravate the injury to myocardium. Expression and activity of CaMKII have been found to be elevated in various conditions of stressed myocardium and in different heart diseases in both animal models as well as heart patients...
March 2017: Experimental and Therapeutic Medicine
Kerstin Boengler, Marko Bulic, Rolf Schreckenberg, Klaus-Dieter Schlüter, Rainer Schulz
BACKGROUND AND PURPOSE: Dysregulation of gap junction-mediated cell coupling contributes to development of arrhythmias and myocardial damage after ischaemia/reperfusion (I/R). Connexin 43 (Cx43) is present at ventricular gap junctions and also in the mitochondria of cardiomyocytes. The dipeptide (2S, 4R)-1-(2-aminoacetyl)-4-benzamidopyrrolidine-2-carboxylic acid (ZP1609) has antiarrhythmic properties and reduces infarct size when given at reperfusion. However, it is unclear, whether ZP1609 targets Cx43-containing mitochondria and affects cardiomyocyte hypercontracture following I/R...
July 2017: British Journal of Pharmacology
Thomas Ravn Lassen, Jan Møller Nielsen, Jacob Johnsen, Steffen Ringgaard, Hans Erik Bøtker, Steen Buus Kristiansen
Left ventricular (LV) remodeling following a myocardial infarction (MI) involves formation of reactive oxygen species (ROS). Paroxetine, a selective serotonin reuptake inhibitor, has an antioxidant effect in the vascular wall. We investigated whether paroxetine reduces myocardial ROS formation and LV remodeling following a MI. In a total of 32 Wistar rats, MI was induced by a 30-min ligation of the left anterior descending artery followed by 7- or 28-day reperfusion. During the 28 days of reperfusion, LV remodeling was evaluated by magnetic resonance imaging (MRI) and echocardiography (n = 20)...
May 2017: Basic Research in Cardiology
Lin Li, Yunfeng Zhou, Yanlin Li, Lili Wang, Lan Sun, Lidong Zhou, Hiderori Arai, Yun Qi, Yang Xu
Ischemia-reperfusion injury is the major manifestation of ischemic heart disease, which facilitates cardiac arrhythmias, heart failure and death. Oxidative stress and apoptosis have been involved in the pathogenesis of myocardial ischemia-reperfusion injury. Modern pharmacological studies have indicated that the extracts and active compounds of Cortex Dictamni exhibit antioxidative and cardiovascular protective activities. This study was designed to investigate the protective effect of aqueous extract of Cortex Dictamni (CDAE) on regulating hypoxia/reoxygenation (H/R)-induced cardiomyocytes oxidative stress and apoptosis...
May 2017: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
Marie Destors, Renaud Tamisier, Louis-Marie Galerneau, Patrick Lévy, Jean-Louis Pepin
Obstructive sleep apnoea syndrome (OSAS) is characterized by recurrent partial or complete pharyngeal collapses during sleep. The pathophysiology of OSAS is complex and multifactorial. Factors influencing upper airway patency include a reduction in upper airway dimensions that can result from both anatomical and functional alterations (obesity, fluid shift or maxillo-facial structural changes), and increased pharyngeal collapsibility owing to reduced neuromuscular compensation and lack of the pharyngeal protective reflex during sleep...
April 2017: La Presse Médicale
Marilen Federico, Enrique L Portiansky, Leandro Sommese, Francisco J Alvarado, Paula G Blanco, Carolina N Zanuzzi, John Dedman, Marcia Kaetzel, Xander H T Wehrens, Alicia Mattiazzi, Julieta Palomeque
KEY POINTS: Spontaneous sarcoplasmic reticulum (SR) Ca(2+) release events increased in fructose-rich diet mouse (FRD) myocytes vs. control diet (CD) mice, in the absence of significant changes in SR Ca(2+) load. In HEK293 cells, hyperglycaemia significantly enhanced [(3) H]ryanodine binding and Ca(2+) /calmodulin-dependent protein kinase II (CaMKII) phosphorylation of RyR2-S2814 residue vs. normoglycaemia. These increases were prevented by CaMKII inhibition. FRD significantly augmented cardiac apoptosis in WT vs...
June 15, 2017: Journal of Physiology
Ye Chen-Izu, Leighton T Izu
The heart has the ability to adjust to changing mechanical loads. The Frank-Starling law and the Anrep effect describe exquisite intrinsic mechanisms the heart has for autoregulating the force of contraction to maintain cardiac output under changes of preload and afterload. Although these mechanisms have been known for more than a century, their cellular and molecular underpinnings are still debated. How does the cardiac myocyte sense changes in preload or afterload? How does the myocyte adjust its response to compensate for such changes? In cardiac myocytes Ca2+ is a crucial regulator of contractile force and in this review we compare and contrast recent studies from different labs that address these two important questions...
June 15, 2017: Journal of Physiology
Tae Yun Kim, Radmila Terentyeva, Karim H F Roder, Weiyan Li, Man Liu, Ian Greener, Shanna Hamilton, Iuliia Polina, Kevin R Murphy, Richard T Clements, Samuel C Dudley, Gideon Koren, Bum-Rak Choi, Dmitry Terentyev
Aims: Plasmamembrane small conductance Ca2+-activated K+ (SK) channels were implicated in ventricular arrhythmias in infarcted and failing hearts. Recently, SK channels were detected in the inner mitochondria membrane (IMM) (mSK), and their activation protected from acute ischaemia-reperfusion injury by reducing intracellular levels of reactive oxygen species (ROS). We hypothesized that mSK play an important role in regulating mitochondrial function in chronic cardiac diseases. We investigated the role of mSK channels in Ca2+-dependent ventricular arrhythmia using rat model of cardiac hypertrophy induced by banding of the ascending aorta thoracic aortic banding (TAB)...
March 1, 2017: Cardiovascular Research
T-M Lee, Nen-Chung Chang, Shinn-Zong Lin
Although endothelin (ET)-1 has been shown to upregulate nerve growth factor (NGF) expression, the molecular mechanisms are largely unknown. Phosphatidylinositol 3-kinase (PI3K)/Akt/glycogen synthase kinase (GSK)-3β signal has been implicated in the regulation of NGF. We investigated whether selective ET receptor blockers attenuated cardiac sympathetic reinnervation through restoring PI3K/Akt/GSK-3β activity. After ligation of the left anterior descending artery, male Wistar rats were randomized to either vehicle, atrasentan (an ETA receptor antagonist) or A-192621 (an ETB receptor antagonist) for 4 weeks...
March 2017: Laboratory Investigation; a Journal of Technical Methods and Pathology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"