Jean-Jacques Mercadier

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The spectral Doppler mitral flow pattern, alone or combined with tissue Doppler mitral annulus velocity, can be used to predict left ventricular (LV) filling pressure in humans, whereas invasive hemodynamic measurements are still required in the rat. This study was undertaken to assess whether LV end-diastolic pressure (LVEDP) can be estimated using Doppler(More)
Block of Na/Ca exchange (NCX) has potential therapeutic applications, in particular, if a mode-selective block could be achieved, but also carries serious risks for disturbing the normal Ca balance maintained by NCX. We have examined the effects of partial inhibition of NCX by SEA-0400 (1 or 0.3 mol/L) in left ventricular myocytes from healthy pigs or mice(More)
BACKGROUND Defects in cardiomyocyte Ca(2+) cycling are a signature feature of heart failure (HF) that occurs in response to sustained hemodynamic overload, and they largely account for contractile dysfunction. Neuronal nitric oxide synthase (NOS1) influences myocyte excitation-contraction coupling through modulation of Ca(2+) cycling, but the potential(More)
We examined the topology of angiotensin-converting enzyme (ACE) mRNA expression, activity, and shedding in myocardial infarction-induced heart failure and sought to elucidate the source of the increased plasma ACE activity in this model. Three months after coronary ligature, lung, scar, and remaining viable left ventricular tissues were analyzed for ACE(More)
Ca/calmodulin-dependent protein kinases II (CaMKII) have important functions in regulating cardiac excitability and contractility. In the present study, we examined whether CaMKII regulated the transient outward K current (Ito) in whole-cell patch-clamped human atrial myocytes. We found that a specific CaMKII inhibitor, KN-93 (20 mmol/L), but not its(More)
AIMS A decrease in L-type calcium current (ICaL) is an important mechanism favouring atrial fibrillation (AF). Here, we aimed to identify pathogenic factors associated with ICaL downregulation. METHODS AND RESULTS Atrial myocytes were isolated from right atrial appendages obtained from 86 adult patients in sinus rhythm with coronary artery disease, aortic(More)
Alterations in RyR2 function have been proposed as a major pathophysiological mechanism of arrhythmias and heart failure (HF). Cardiac FKBP12.6 overexpression protects against myocardial infarction-induced HF and catecholamine-promoted ventricular arrhythmias. We tested the hypothesis that FKBP12.6 overexpression protects against maladaptive LVH and(More)
BACKGROUND Heart failure often complicates myocardial infarction (MI), and sarcoplasmic/endoplasmic reticulum Ca2+-ATPase (SERCA2a) is underexpressed in the failing myocardium. We examined the effect of preexisting cardiac SERCA2a protein overexpression on rat survival and left ventricular (LV) remodeling after MI. METHODS AND RESULTS Baseline myocardial(More)
In cardiac myocytes, Ca2+ is the second messenger of various physiological processes, including the excitation-contraction coupling phenomenon. Here, we examined how Ca2+ regulates cardiac myocyte apoptosis. Using an adult rat ventricular myocyte culture model, we found that ceramide (Cer) induces an apoptotic process that is highly sensitive to calcium: it(More)
Tetracycline is a powerful tool for controlling the expression of specific transgenes (TGs) in various tissues, including heart. In these mouse systems, TG expression is repressed/enhanced by adding doxycycline (Dox) to the diet. However, Dox has been shown to attenuate matrix metalloproteinase (MMP) expression and activity in various tissues, and MMP(More)