H9c2 is a clonal myogenic cell line derived from embryonic rat ventricle that can serve as a surrogate for cardiac or skeletal muscle in vitro. Using whole cell clamp with H9c2 myotubes, we observed that depolarizing pulses activated slow outward K+ currents and then slow tail currents. The K+ currents were abolished in a Ca2+-free external solution, indicating that they were Ca2+-activated K+ ...

It is known that glutamate (Glu), the major excitatory amino acid in the central nervous system, can be an essential source for cell energy metabolism. Here we investigated the role of the plasma membrane Na(+)/Ca(2+) exchanger (NCX) and the excitatory amino acid transporters (EAATs) in Glu uptake and recycling mechanisms leading to ATP synthesis. We used different cell lines, such as SH-SY5Y n...

Natriuretic peptide receptor 3 (NPR3) is a clearance receptor by binding and internalizing natriuretic peptides (NPs) for ultimate degradation. Patients with cardiac failure show elevated NPs. NPs are linked to poor long-term survival because of their apoptotic effects. However, the underling mechanisms have not been identified yet. Here we report the role of NPR3 in anti-apoptosis via the brea...

Diabetic cardiomyopathy (DCM) remains the major cause of death associated with diabetes. Researchers have demonstrated the importance of impaired cardiac insulin signaling in this process. Insulin resistance (IR) is an important predictor of DCM. Previous studies examining the dynamic changes in autophagy during IR have yielded inconsistent results. This study aimed to investigate the dynamic c...

Specific DNA fragments complementary to the 3' untranslated regions of the beta-, alpha-cardiac, and alpha-skeletal actin mRNAs were used as in situ hybridization probes to examine differential expression and distribution of these mRNAs in primary myogenic cultures. We demonstrated that prefusion bipolar-shaped cells derived from day 3 dissociated embryonic somites were equivalent to myoblasts ...

Mild and nonlethal heat shock (i.e., hyperthermia) is known to protect the myocardium and cardiomyocytes against ischemic injury. In the present study, we have shown that heat shock regulates the respiration of cultured neonatal cardiomyocytes (cardiac H9c2 cells) through activation of nitric oxide synthase (NOS). The respiration of cultured cardiac H9c2 cells subjected to mild heat shock at 42...

BACKGROUND Diabetes has been regarded as an inflammatory condition which is associated with left ventricular diastolic dysfunction (LVDD). The purpose of this study was to examine the expression levels of macrophage migration inhibitory factor (MIF) and G protein-coupled receptor kinase 2 (GRK2) in patients with early diabetic cardiomyopathy, and to investigate the mechanisms involved in MIF ex...

Myosin light chain kinases have been isolated from rat thigh and rabbit skeletal muscle and cultured rat myoblasts. From these preparations, two types of kinases can be distinguished: calcium-dependent and calcium-independent. Both types of kinases can phosphorylate isolated P-light chains of myosin from several sources (skeletal muscle, cardiac muscle, and platelet). Data are shown which suppo...

The mitochondrial enzyme monoamine oxidase (MAO), its isoform MAO-A, plays a major role in reactive oxygen species-dependent cardiomyocyte apoptosis and postischemic cardiac damage. In the current study, we investigated whether sphingolipid metabolism can account for mediating MAO-A- and reactive oxygen species-dependent cardiomyocyte apoptosis. In H9c2 cardiomyoblasts, MAO-A-dependent reactive...

Background: Increased cardiomyocyte apoptosis under high glucose condition contributes to diabetic cardiomyopathy. Degradation of cardiac Connexin43 (Cx43) has been associated with cardiac dysfunction in diabetic heart. Clinical and experimental studies suggested that metformin (Met) exhibits cardioprotective properties against diabetes. Aim: The aim of this study was to investigate the effect ...