Group leader:
- Prof. Dr Péter Pál Nánási
Members of the research group:
- Prof. Dr Tamás Bányász
- Prof. Dr János Magyar
- Dr Norbert Szentandrássy, Ph.D
- Dr Balázs Horváth, Ph.D
A short summary of the scientific work carried out by the research group:
In recent years, we have carried out multidisciplinary research in the field of cellular cardiac electrophysiology. The vast majority of our cardio physiology experiments are performed on ventricular myocardium cells isolated from dogs, but if necessary we also use ventricular myocardium of guinea pig or rabbit origin. For our measurements, we use conventional microelectrode technique, traditional voltage-clamp technique and action potential clamp technique, which are accompanied with intracellular calcium concentration measurements or with contractility measurements. We repeatedly examine the frequency-dependent characteristics of heart function, with particular attention to the events occurring during ventricular repolarization. The primary target of our research is the kinetic characteristics of the calcium-dependent ion currents of the ventricular myocardium, the molecular mechanisms of their regulation, and the behavior of these ion currents during physiological repolarization and under pathological conditions. In our action potential voltage-clamp experiments, our goal is to present the true profile of individual ion currents, when we visualize the current profiles under the action potential using selective ion channel blockers. As a special application of the action potential voltage-clamp, we introduced the so-called "onion peeling" method, during which several ion currents can be measured sequentially on a single heart muscle cell. We also examine the individual proarrhythmic and antiarrhythmic mechanisms, with particular regard to the characteristics of early afterdepolarizations and the changes in the beat-to-beat variability of the action potential duration under different conditions. Overall, the ultimate goal of our research is a better understanding of proarrhythmic and antiarrhythmic mechanisms, which may enable the development of more effective antiarrhythmic therapy in the long term.
List of the 10 most important publications related to the research work:
Bányász T, Fülöp L, Magyar J, Szentandrássy N, Varró A, Nánási PP: Endocardial versus epicardial differences in L-type calcium current in canine ventricular myocytes studied by action potential voltage clamp. Cardiovasc Res 2003;58:66-75 [IF=5.164]
Szentadrássy N, Bányász T, Bíró T, Szabó G, Tóth B, Magyar J, Lázár J, Varró A, Kovács L, Nánási PP: Apico-basal inhomogeneity in distribution of ion channels in canine and human ventricular myocardium. Cardiovasc Res 2005;65:851-860 [IF=5.283]
Birinyi P, Tóth A, Jóna I, Acsai K, Almássy J, Nagy N, Prorok J, Gherasim I, Papp Z, Hertelendi Z, Szentandrássy N, Bányász T, Fülöp F, Papp JGy, Varró A, Nánási PP, Magyar J: The Na+/Ca2+ exchange blocker SEA0400 fails to enhance cytosolic Ca2+ transient and contractility in canine ventricular cardiomyocytes. Cardiovasc Res 2008;78:476-484 [IF=5.947]
Jost N, Acsai K, Horváth B, Bányász T, Bitay M, Bogáts G, Nánási PP: Contribution of IKr and IK1 to ventricular repolarization in canine and human myocytes. Is there any influence of action potential duration? Basic Res Cardiol 2009;104:33-41 [IF=5.973]
Bányász T, Horváth B, Virág L, Bárándi L, Szentandrássy N, Harmati G, Magyar J, Marangoni S, Zaza A, Varró A, Nánási PP: Reverse rate dependency is an intrinsic property of canine cardiac preparations. Cardiovasc Res 2009;84:237-244 [IF= 5.801]
Bárándi L, Virág L, Jost N, Horváth Z, Koncz I, Papp R, Harmati G, Horváth B, Szentandrássy N, Bányász T, Magyar J, Zaza A, Varró A, Nánási PP: Reverse rate-dependent changes are determined by baseline action potential duration in mammalian and human ventricular preparations. Basic Res Cardiol 2010;105:315-323 [IF=6.128]
Horváth B, Váczi K, Hegyi B, Gönczi M, Dienes B, Kistamás K, Bányász T, Magyar J, Baczkó I, Varró A, Seprényi Gy, Csernoch L, Nánási PP, Szentandrássy N: Sarcolemmal Ca2+-entry through L-type Ca2+ channels controls the profile of Ca2+-activated Cl- current in canine ventricular myocytes. J Mol Cell Cardiol 2016; 97:125-139 [IF=5.218]
Horváth B, Hézső T, Szentandrássy N, Kistamás K, Árpádffy-Lovas T, Varga R, Gazdag P, Veress R, Dienes Cs, Baranyai D, Almássy J, Virág L, Nagy N, Baczkó I, Magyar J, Bányász T, Varró A, Nánási P: Late sodium current in human, canine and guinea pig ventricular myocardium. J Mol Cell Cardiol 2020;139:14-23. [IF=5.055]
Horváth B, Kiss D, Dienes Cs, Hézső T, Kovács Zs, Szentandrássy N, Almássy J, Magyar J, Bányász T, Nánási PP: Ion current profiles in canine ventricular myocytes obtained by the “onion peeling” technique. J Mol Cell Cardiol 2021;158:153-162. [IF=5.055]
Horváth B, Kovács ZsM, Dienes Cs, Óvári J, Szentandrássy N, Magyar J, Bányász T, Varró A, Nánási PP: Conductance changes of Na+ channels during the late Na+ current flowing under action potential voltage clamp conditions in canine, rabbit and guinea pig ventricular myocytes. Pharmaceuricals 2023; 16, Art#: 560. [IF=5.863]