Stéphanie C.M. Choisy

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The atrioventricular node (AVN) is a key component of the cardiac pacemaker-conduction system. This study investigated the electrophysiology of cells isolated from the AVN region of adult mouse hearts, and compared murine ionic current magnitude with that of cells from the more extensively studied rabbit AVN. Whole-cell patch-clamp recordings of ionic(More)
Investigations into the functional modulation of the cardiac Na(+)-Ca(2+) exchanger (NCX) by acute β-adrenoceptor/PKA stimulation have produced conflicting results. Here, we investigated (i) whether or not β-adrenoceptor activation/PKA stimulation activates current in rabbit cardiac myocytes under NCX-'selective' conditions and (ii) if so, whether a(More)
BACKGROUND The atrioventricular node (AVN) is a key component of the cardiac pacemaker-conduction system. Although it is known that receptors for the peptide hormone endothelin-1 (ET-1) are expressed in the AVN, there is very little information available on the modulatory effects of ET-1 on AVN electrophysiology. This study characterises for the first time(More)
The atrioventricular node (AVN) is a vital component of the pacemaker-conduction system of the heart, co-ordinating conduction of electrical excitation from cardiac atria to ventricles and acting as a secondary pacemaker. The electrical behaviour of the AVN is modulated by vagal activity via activation of muscarinic potassium current, IKACh. However, it is(More)
Accumulating evidence suggests that steady-state K(+) currents modulate excitability and action potential duration, particularly in cardiac cell types with relatively abbreviated action potential plateau phases. Despite representing potential drug targets, at present these currents and their modulation are comparatively poorly characterized. Therefore, we(More)
Background inward sodium current (IB,Na) that influences cardiac pacemaking has been comparatively under-investigated. The aim of this study was to determine for the first time the properties and role of IB,Na in cells from the heart's secondary pacemaker, the atrioventricular node (AVN). Myocytes were isolated from the AVN of adult male rabbits and mice(More)
AIMS Noradrenaline plays an important role in the modulation of atrial electrophysiology. However, the identity of the modulated channels, their mechanisms of modulation, and their role in the action potential remain unclear. This study aimed to investigate the noradrenergic modulation of an atrial steady-state outward current (IKss). METHODS AND RESULTS(More)
Hypertension-induced structural remodeling of the left atrium (LA) has been suggested to involve the renin-angiotensin system. This study investigated whether treatment with an angiotensin receptor blocker, candesartan, regresses atrial remodeling in spontaneously hypertensive rats (SHR). Effects of treatment with candesartan were compared to treatment with(More)
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