Restitution of action potential duration (APD) is thought to be critical in activation instability. Although restitution is used to predict APD during sequential changes in diastolic interval (DI), currently used protocols to determine restitution do not use sequential changes in DI. We explored restitution using a new pacing protocol to change DI sequentially and independently of APD. Transmem...

Rapid epithelial repair (restitution) after injury is required to maintain barrier function of the gastrointestinal mucosa and skin and is thought to be a highly ATP-dependent process that would be inhibited under hypoxic conditions. However, little is known about the metabolic pathways required for restitution. Thus, this study was undertaken to evaluate, in vitro, the role of oxidative respir...

Hoit, Brian D., Vivek J. Kadambi, Daniel A. Tramuta, Nancy Ball, Evangelia G. Kranias, and Richard A. Walsh. Influence of sarcoplasmic reticulum calcium loading on mechanical and relaxation restitution. Am. J. Physiol. Heart Circ. Physiol. 278: H958–H963, 2000.—Mechanical and relaxation restitution represent the restoration of contractile force and relaxation, respectively, in premature beats h...

In the present work, the effect of the restitution coefficient on the numerical results for a binary mixture system of sand particles and char particles in a bubbling fluidized bed with a huge difference between the particles in terms of density and volume fraction has been studied based on two-fluid model along with the kinetic theory of granular flow. Results show that the effect of restituti...

Sudden cardiac death remains a major public health problem in the United States. Ventricular fibrillation (VF) is the most common arrhythmia that directly leads to sudden cardiac death. However, the mechanisms of VF are unclear. Recently,1 2 different types of VF have been demonstrated in isolated, perfused rabbit hearts linked to the electrical restitution properties of the heart (ie, the dyna...

We investigated the function of the monocarboxylate transporter MCT1 in restitution of gastric surface mucous cells. Restitution is the repair mechanism by which cells migrate to cover an injured area. Cell migration after injury is dependent upon glycolysis, which under some conditions yields the waste product lactate. We used the bioflavenoid phloretin, a known inhibitor of MCT1, to block lac...

BACKGROUND T-wave alternans, which is associated with the genesis of cardiac fibrillation, has recently been related to discordant action potential duration (APD) alternans. However, the cellular electrophysiological mechanisms responsible for discordant alternans are poorly understood. METHODS AND RESULTS We simulated a 2D sheet of cardiac tissue using phase 1 of the Luo-Rudy cardiac action ...

The restitution kinetics of action potential duration (APD) were investigated in paced canine Purkinje fibers (P; n = 9) and endocardial muscle (M; n = 9), in isolated, perfused canine left ventricles during ventricular fibrillation (VF; n = 4), and in endocardial muscle paced at VF cycle lengths (simulated VF; n = 4). Restitution was assessed with the use of two protocols: delivery of a single...

We sought to explore the distribution pattern of Na(+) channels across ventricular wall, and to determine its functional correlates, in the guinea pig heart. Voltage-dependent Na(+) channel (Na(v)) protein expression levels were measured in transmural samples of ventricular tissue by Western blotting. Isolated, perfused heart preparations were used to record monophasic action potentials and vol...

Günzel, D., P. Florian, J. F. Richter, H. Troeger, J. D. Schulzke, M. Fromm, and A. H. Gitter. Restitution of single-cell defects in the mouse colon epithelium differs from that of cultured cells. Am J Physiol Regul Integr Comp Physiol 290: R1496–R1507, 2006. First published January 5, 2006; doi:10.1152/ajpregu.00470.2005.—Integrity of colon epithelium is of crucial importance and, as small def...