Frantisek Bartak

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OBJECTIVE To hypothesize that reduced L-type calcium current with consequent shortening of cardiac repolarization is present in a clinically relevant porcine model of hyperdynamic septic shock. Myocardial depression is a well-recognized manifestation of sepsis and septic shock. Reduction of L-type calcium current was demonstrated to contribute to the(More)
The basic electrophysiological manifestations of the ventricular myocardium of twelve 7- to 12-week human embryos were measured with a glass electrode and a programmed stimulation technique. The resting membrane potential value was 79.37 +/- 0.34 mV and the overshoot 32.7 +/- 0.57 mV; the action potential (AP) duration at 1 Hz stimulation frequency was(More)
The aim of the study was to describe and attempt to explain certain specific features of electromechanical coupling in the rabbit myocardium. Electromechanical correlations in the papillary muscles of the right ventricle of adult rabbit hearts were studied by a programmed stimulation technique. The duration of action potentials (AP) was measured in the(More)
The effects of calcitonin gene-related peptide (CGRP) on the transient outward current (Ito) and the L-type calcium current (ICa,L) were investigated in isolated rat ventricular cardiomyocytes using the whole-cell, patch-clamp technique. CGRP influenced neither the amplitude nor the time course of ICa,L. On the other hand, at all membrane potentials at(More)
To elucidate the postnatal development of electrogenesis in the rat ventricular myocardium, we investigated specimens of the right ventricles of rats of different ages (newborn, 2 days, 5 days, 10 days and adult) by means of glass microelectrodes and a programmable stimulator. The resting membrane potential rose from -82 mV (newborn) to -89.6 mV (adult).(More)
Using glass microelectrodes, the authors measured basic electrophysiological parameters of the true pacemaker cells of the rabbit in an attempt to elucidate the postnatal drop in the frequency of action potentials produced by the sinoatrial node. The average rate of slow diastolic depolarization falls markedly between birth and adulthood, while the duration(More)
Using the glass microelectrode technique we measured the effect of adrenaline (ADR, 10(-5) mol . l-1) and acetylcholine (ACh, 10(-5) mol . l-1) on action potentials (AP) of the ventricular myocardium of 8- to 11-week-old human embryos. ACh prolonged the AP (by 20%), without affecting voltage of the plateau phase. ADR markedly elevated the plateau phase (by(More)
The effect of paired stimulation on the action potentials of the working ventricular myocardium of newborn and adult rabbits was studied with the aim of elucidating the postnatal development of electrogenesis in cardiac cells. After a 2 minutes' rest pause we applied two identical rectangular electric pulses (duration 0.1-1 ms, voltage double the(More)
Using the glass microelectrodes techniques, we analysed the causes of the shortening of the ventricular myocardial action potentials (AP) of albino rats during postnatal development. Delayed outward currents were blocked with tetraethylammonium (TEA) in 20 mmol.l-1 concentration. TEA led to prolongation of action potentials and to accentuation of frequency(More)