Impaired Systolic and Diastolic Left Ventricular Function in Children with Chronic Kidney Disease - Results from the 4C Study.

Children with chronic kidney disease suffer from excessive cardiovascular mortality and early alterations of the cardiovascular system. Tissue doppler imaging is a validated echocardiographic tool to assess early systolic and diastolic cardiac dysfunction. We hypothesized that tissue Doppler velocities would reveal reduced cardiac function in children with chronic kidney disease compared to healthy children.

The MLCK-mediated alpha1-adrenergic inotropic effect in atrial myocardium is negatively modulated by PKCepsilon signaling.

The present study examined the role of myosin light chain kinase (MLCK), PKC isozymes, and inositol 1,4,5-trisphosphate (IP(3)) receptor in the positive inotropic effect of alpha(1)-adrenergic stimulation in atrial myocardium. We measured inotropic effects of phenylephrine (0.3-300 microM) in isolated left atrial preparations (1 Hz, 37 degrees C, 1.

Key role of myosin light chain (MLC) kinase-mediated MLC2a phosphorylation in the alpha 1-adrenergic positive inotropic effect in human atrium.

Objective: Mechanisms of the positive inotropic response to alpha(1)-adrenergic stimulation in the heart remain poorly understood, but recent evidence in rat papillary muscle suggests an important role of regulatory myosin light chain (MLC2) phosphorylation. This study investigated alpha(1)-adrenergic contractile effects and the role of MLC kinase (MLCK)-dependent phosphorylation of MLC2 in human atrial muscle strips.

Methods: Force measurement was performed on electrically stimulated atrial muscle strips (n=140; 20 hearts) in the presence of the beta-blocker nadolol.