The effect of amiodarone on the expression of myosin isoforms and the growth of neonatal rat cardiac muscle cells in culture was studied by native gel electrophoresis, assays of DNA and protein synthesis, and electron microscopy. Cardiac myocytes exposed to amiodarone in the absence of triiodothyronine (T3) showed predominant V1. When cardiac myocytes were exposed to amiodarone in the presence ...

In freshly dissociated uterine myocytes, the outward current is carried by K+ through channels highly selective for K+. Typically, nonpregnant myocytes have rather noisy K+ currents; half of them also have a fast-inactivating transient outward current (ITO). In contrast, the current records are not noisy in late pregnant myocytes, and ITO densities are low. The whole-cell IK of nonpregnant myoc...

Obesity and type 2 diabetes are associated with chronically elevated systemic levels of IL-6, a pro-inflammatory cytokine with a role in skeletal muscle metabolism that signals through the IL-6 receptor (IL-6Rα). We hypothesized that skeletal muscle in obesity-associated type 2 diabetes develops a resistance to IL-6. By utilizing western blot analysis, we demonstrate that IL-6Rα protein was dow...

Thyroid hormones play an important role in cardiac electrophysiology through both genomic and nongenomic mechanisms of action. The effects of triiodothyronine (T(3)) on the electrophysiological properties of ventricular myocytes isolated from euthyroid and hypothyroid rats were studied using whole cell patch clamp techniques. Hypothyroid ventricular myocytes showed significantly prolonged actio...

Previous studies on myocytes isolated from rat hearts 3 wk after myocardial infarction (MI) demonstrated increased cell length, reduced Na(+)/Ca(2+) exchange (NCX1) activity, altered contractility, and intracellular Ca(2+) concentration ([Ca(2+)](i)) transients. In the present study, we investigated whether NCX1 overexpression in MI myocytes would restore contraction and [Ca(2+)](i) transients ...

Differentiation cultures of embryonic stem (ES) cells can be a useful in vitro system for understanding cardiac myocyte development. However, cell morphometry, sarcomere development, and functional cell-cell junction formation have not been examined in detail to determine whether ES cell-derived cardiac myocytes exhibit structural and functional characteristics similar to cardiac myocytes withi...

cell replacement therapy has provided the basis for future clinical applications to treat central nervous system injury, a common result of car accidents. induced functional motoneurons are an option for replacing the lost motoneurons. adipose derived stem cells (adscs) are an appropriate source of cells for autologous cell therapy with the ability of neural differentiation. in this study, adsc...

High-mobility group box 1 (HMGB1) is increased in the myocardium under pressure overload (PO) and involved PO-induced cardiac remodeling. The mechanisms of upregulation HMGB1 expression have not been fully elucidated. In present study, a mouse transverse aortic constriction (TAC) model was used, an angiotensin II (Ang II) type (AT1) receptor inhibitor (losartan) or Ang 2 (AT2) (PD123319) admini...

Atrial cardiomyocytes make an important contribution to the refilling of ventricles with blood, which enhances the subsequent ejection of blood from the heart. The dependence of cardiac function on the contribution of atria becomes increasingly important with age and exercise. We know much less about the calcium signals that link electrical depolarisation to contraction within atrial myocytes i...

The goal of the present study was to assess whether cardiac myocytes exposed to anoxia-reoxygenation (A/R) could generate a chemotactic gradient for polymorphonuclear neutrophil (PMN) transendothelial migration. Exposure of neonatal mouse cardiac myocytes to A/R induced an oxidant stress in the myocytes. Supernatants obtained from A/R-conditioned myocytes promoted mouse PMN migration across mou...