Torsten Christ

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BACKGROUND The molecular mechanism of increased background inward rectifier current (IK1) in atrial fibrillation (AF) is not fully understood. We tested whether constitutively active acetylcholine (ACh)-activated I(K,ACh) contributes to enhanced basal conductance in chronic AF (cAF). METHODS AND RESULTS Whole-cell and single-channel currents were measured(More)
The cardiac action potential is generated by a concerted action of different ion channels and transporters. Dysfunction of any of these membrane proteins can give rise to cardiac arrhythmias, which is particularly true for the repolarizing potassium channels. We suggest that an increased repolarization current could be a new antiarrhythmic principle,(More)
BACKGROUND The ultrarapid outward current I(Kur) is a major repolarizing current in human atrium and a potential target for treating atrial arrhythmias. The effects of selective block of I(Kur) by low concentrations of 4-aminopyridine or the biphenyl derivative AVE 0118 were investigated on right atrial action potentials (APs) in trabeculae from patients in(More)
BACKGROUND Clinical and experimental evidence suggest that the parasympathetic nervous system is involved in the pathogenesis of atrial fibrillation (AF). However, it is unclear whether changes in G-protein-coupled inward rectifying K(+) current (I(K,ACh)) contribute to chronic AF. METHODS AND RESULTS In the present study, we used electrophysiological(More)
Human mesenchymal stem cells (hMSC) have gained considerable interest due to their potential use for cell replacement therapy and tissue engineering. One strategy is to differentiate these bone marrow stem cells in vitro into cardiomyocytes prior to implantation. In this context ion channels can be important functional markers of cardiac differentiation. At(More)
BACKGROUND AND PURPOSE This study was designed to establish the pathology-specific inhibitory effects of the IKur/Ito/IK,ACh blocker AVE0118 on atrium-selective channels and its corresponding effects on action potential shape and effective refractory period in patients with chronic AF (cAF). EXPERIMENTAL APPROACH Outward K+-currents of right atrial(More)
BACKGROUND Although downregulation of L-type Ca2+ current (I(Ca,L)) in chronic atrial fibrillation (AF) is an important determinant of electrical remodeling, the molecular mechanisms are not fully understood. Here, we tested whether reduced I(Ca,L) in AF is associated with alterations in phosphorylation-dependent channel regulation. METHODS AND RESULTS We(More)
Within the field of new antiarrhythmic compounds, the interesting idea of activating human ether-a-go-go-related gene (HERG1) potassium channels has recently been introduced. Potentially, drugs that increase HERG1 channel activity will augment the repolarizing current of the cardiac myocytes and stabilize the diastolic interval. This may make the myocardium(More)
The zebrafish has recently emerged as an excellent model for studies of heart development and regeneration. The physiology of the zebrafish heart has been suggested to resemble that of the human heart in many aspects, whereas, in contrast to mammals, the zebrafish has a remarkable ability to regenerate after heart injury. Thus, zebrafish have been proposed(More)
BACKGROUND AND PURPOSE It has been proposed that BRL37344, SR58611 and CGP12177 activate β₃-adrenoceptors in human atrium to increase contractility and L-type Ca(2+) current (I(Ca-L)). β₃-adrenoceptor agonists are potentially beneficial for the treatment of a variety of diseases but concomitant cardiostimulation would be potentially harmful. It has also(More)