Pierre Ducouret

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Slowing of cardiac pacemaking induced by cholinergic input is thought to arise from the opening of potassium channels caused by muscarinic receptor stimulation. In mammalian sinoatrial node cells, however, muscarinic stimulation also inhibits the hyperpolarization-activated current (If), which is involved in the generation of pacemaker activity and its(More)
BACKGROUND Direct myocardial effects of volatile anesthetics have been studied in various animal species in vitro. This study evaluated the effects of equianesthetic concentrations of desflurane, sevoflurane, isoflurane, and halothane on contractile parameters of isolated human atria in vitro. METHODS Human right atrial trabeculae, obtained from patients(More)
1. In order to investigate the role of KATP channel activation and repolarization dispersion on the 'border zone' arrhythmias induced by ischaemia-reperfusion, the effects of glibenclamide and bimakalim, agents modifying action potential (AP) duration, were studied in an in vitro model of myocardial 'border zone'. 2. The electrophysiological effects of 10(More)
BACKGROUND We studied the potential neuroprotective effects of halothane and desflurane, compared with the awake state, on infarct size following 2 h of intraluminal middle cerebral artery occlusion (MCAo) and 22 h of reperfusion. METHODS Male Sprague-Dawley rats were anaesthetized with desflurane or halothane, intubated, and mechanically ventilated. Mean(More)
Electrophysiologic effects of K(ATP) channel openers (KCOs) are rarely studied for tissue and species specificity, and use-dependent investigations in human tissues are lacking. We therefore investigated in vitro the concentration-dependent effects of the KCO bimakalim [from 10 nM to 10 microM, at 1,000 ms of cycle length (CL) and 37 degrees C] on human(More)
BACKGROUND The authors examined the role of adenosine triphosphate-sensitive potassium channels and adenosine A(1) receptors in sevoflurane-induced preconditioning on isolated human myocardium. METHODS The authors recorded isometric contraction of human right atrial trabeculae suspended in oxygenated Tyrode's solution (34 degrees C; stimulation frequency,(More)
Experimental infection of macaques with pathogenic strains of simian immunodeficiency virus (SIV) represents one of the most relevant animal models for studying HIV pathogenesis. In this study, we demonstrated a significant decrease in the generation of CD4+ T cells from bone marrow (BM) CD34+ progenitors in macaques infected with SIVmac251. This decrease(More)
1 The action of quinidine sulphate 50 muM has been investigated on frog auricular trabeculae transmembrane currents recorded with a double sucrose gap apparatus. Results were obtained either in current or in voltage clamp conditions. 2 Quinidine modified the time course of repetitive activity elicited by long lasting depolarizing currents and reduced the(More)
BACKGROUND The authors examined the effect of ketamine and its S(+) isomer on isolated human myocardium submitted to hypoxia-reoxygenation in vitro. METHODS The authors studied isometric contraction of human right atrial trabeculae suspended in an oxygenated Tyrode's modified solution at 34 degrees C. Ten minutes before a 30-min hypoxic period followed by(More)
The effects of butoprozine on cardiac membrane currents of frog atrial and ferret ventricular fibres were investigated in voltage clamp conditions by means of the double sucrose gap technique. Comparison was made with amiodarone and verapamil. Butoprozine was found to decrease the fast sodium and slow calcium inward currents and the delayed outward current(More)