Andrzej Beręsewicz

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The development of H2O2-induced changes in membrane potentials, membrane currents and corresponding contractile activity (shortening) were studied in rat and guinea-pig ventricular myocytes using the suction-pipette whole-cell clamp method. The cells exhibited a different sensitivity to 30 microM H2O2 in terms of time development of the changes, which were(More)
In this study simultaneous measurements of action potentials and force of contraction of isolated ventricular muscle from cat and calf hearts were performed under stimulated steady-state and rested-state conditions. It is shown that time-to-peak force of the rested-state contraction correlates well with electrically induced changes in the duration of the(More)
The effect of ischemic preconditioning and superoxide dismutase (SOD) on endothelial glycocalyx and endothelium-dependent vasodilation in the postischemic isolated guinea-pig hearts was examined. Seven groups of hearts were used: group 1 underwent sham aerobic perfusion; group 2 was subjected to 40 min global ischemia without reperfusion; group 3, 40 min(More)
Evidence indicates that ischemia/reperfusion (IR) results in endothelial dysfunction and neutrophil adhesion in the post-ischemic myocardium and that ischemic preconditioning (IPC), superoxide dismutase (SOD), and anti-endothelin-1 (ET-1) interventions prevent these effects. We tested the hypothesis that ET-1-induced superoxide (O(2)(-)) generation mediates(More)
The effects of perfusate calcium reduction, allopurinol and dimethylthiourea on reperfusion-induced arrhythmias and purine wash-out in isolated rabbit and rat hearts were compared. The overall incidence of reperfusion-induced ventricular tachycardia (VT) was 88% and 94% and that of ventricular fibrillation (VF) was 44% and 88% in the control rabbit and rat(More)
Ceramide signalling has been implicated in the mechanism of myocardial ischemia/reperfusion injury (IR). This study tested the hypothesis that ceramides containing a specific amino-linked acyl residue mediate the injury, and that ischemic preconditioning (IPC) affords myocardial protection because it prevents increased ceramide accumulation in IR(More)
OBJECTIVE A proposal that injury in ischaemic/reperfused rat heart is critically dependent on the availability of free iron rather than on the efficiency of O2-. and H2O2 production was examined. METHODS Isolated working rat hearts from 152 male Wistar rats (200-250 g weight), subjected to 20-40 min of global ischaemia and reperfused for 30 min, were(More)
NO has been implicated in the mechanism of ischaemic preconditioning. To verify this hypothesis further we have attempted to reproduce effects of ischaemic preconditioning by nitric oxide donors administration prior to the ischaemia. The effect of glyceryl trinitrate (GTN) and 3-morpholino-sydnonimine-hydrochloride (SIN- 1), NO donors, on reperfusion(More)
STUDY OBJECTIVE The aim was to evaluate the regulation of contractility by autonomic stimulation in the necrotic stage of cardiomyopathy in male Syrian hamsters. DESIGN The electrical and contractile activity of isolated intracellularly stimulated ventricular myocytes has been recorded and dose-response curves to [Ca2+]o, and to beta adrenergic, alpha(More)
Seasonality in endothelial dysfunction and oxidative stress was noted in humans and rats, suggesting it is a common phenomenon of a potential clinical relevance. We aimed at studying (i) seasonal variations in cardiac superoxide (O(2)(-)) production in rodents and in 8-isoprostane urinary excretion in humans, (ii) the mechanism of cardiac O(2)(-)(More)