Search results for "Myocytes"
showing 10 items of 117 documents
Ceramide inhibits Kv currents and contributes to TP-receptor-induced vasoconstriction in rat and human pulmonary arteries
2011
et al.
Research of cardiomyocyte precursors in adult rat heart
2006
Recent reports supported the existence of stem cells in adult hearts. However, phenotype and localization of these cells have not been completely described and it is unknown if cardiac regenerative potential differs from one subject to another. The aims of our work were to identify different populations of cardiac stem cells by the analysis of specific markers and to evaluate the expression variability of these markers in 12 adult rat hearts. The expression of CD9, taube nuss and nanog suggests the presence of stem cells from the earliest stages of embryogenesis in adult myocardium. Their different expression could be associated to the degree of stem cell differentiation. CD34 and c-Kit ant…
MiR-133 Modulates the β1Adrenergic Receptor Transduction Cascade.
2014
Rationale : The sympathetic nervous system plays a fundamental role in the regulation of myocardial function. During chronic pressure overload, overactivation of the sympathetic nervous system induces the release of catecholamines, which activate β-adrenergic receptors in cardiomyocytes and lead to increased heart rate and cardiac contractility. However, chronic stimulation of β-adrenergic receptors leads to impaired cardiac function, and β-blockers are widely used as therapeutic agents for the treatment of cardiac disease. MicroRNA-133 (miR-133) is highly expressed in the myocardium and is involved in controlling cardiac function through regulation of messenger RNA translation/stability. …
Vascular effects of sildenafil in patients with pulmonary fibrosis and pulmonary hypertension: an ex vivo/in vitro study
2015
Sildenafil improves the 6-min walking distance in patients with idiopathic pulmonary fibrosis (IPF) and right-sided ventricular systolic dysfunction.We analysed the previously unexplored role of sildenafil on vasoconstriction and remodelling of pulmonary arteries from patients with IPF and pulmonary hypertension (PH) ex vivo. Pulmonary arteries from 18 donors without lung disease, nine IPF, eight PH+IPF and four PH patients were isolated to measure vasodilator and anti-contractile effects of sildenafil in isometric organ bath. Ventilation/perfusion was explored in an animal model of bleomycin lung fibrosis.Sildenafil relaxed serotonin (5-HT) pre-contracted pulmonary arteries in healthy dono…
Characteristics of l-carnitine import into heart cells
2007
Abstract l -carnitine is an essential cofactor for the transport of fatty acids across the mitochondrial membranes. l -carnitine can be provided by food products or biosynthesized in the liver. After intestinal absorption or hepatic biosynthesis, l -carnitine is transferred to organs whose metabolism is dependent upon fatty acid oxidation, such as the skeletal muscle and the heart. The intracellular transport of l -carnitine into the cell requires specific transporters and today, several of these have been characterized. Most of them belong to the solute carrier family. Heart is one of the major target for carnitine transport and use, however basic properties of carnitine uptake by heart ce…
β-Adrenoceptors differentially regulate vascular tone and angiogenesis of rat aorta via ERK1/2 and p38
2014
β-Adrenoceptors (β-ARs) modulate ERK1/2 and p38 in different cells, but little is known about the contribution of these signaling pathways to the function of β-ARs in vascular tissue. Immunoblotting analysis of rat aortic rings, primary endothelial (ECs) and smooth muscle cells (SMCs) isolated from aorta showed that β-AR stimulation with isoprenaline activated p38 in aortic rings and in both cultured cell types, whereas it had a dual effect on ERK1/2 phosphorylation, decreasing it in ECs while increasing it in SMCs. These effects were reversed by propranolol, which by itself increased p-ERK1/2 in ECs. Isoprenaline β-AR mediated vasodilation of aortic rings was potentiated by the ERK1/2 inhi…
Effects of cerivastatin on adrenergic pathways, hypertrophic growth and TGFbeta expression in adult ventricular cardiomyocytes.
2010
Abstract The effects of statin treatment in the setting of heart failure have already been shown. Nevertheless, there is little knowledge about its influence on adrenergic pathways in cardiomyocytes. Therefore, this study investigated the impact of cerivastatin on adrenoceptor-mediated signalling pathways in isolated adult ventricular cardiomyocytes. It focused on two endpoints: hypertrophic growth and TGFbeta expression. Cultured cardiomyocytes were used to study rac activation (analysed by its translocation into the membrane fraction), ROS formation (H 2 DCF fluorescence) and hypertrophic growth ( 14 C-phenylalanine incorporation). Alpha- and beta-adrenoceptor stimulation showed significa…
Paradoxically, iron overload does not potentiate doxorubicin-induced cardiotoxicity in vitro in cardiomyocytes and in vivo in mice
2015
Doxorubicin (DOX) is known to induce serious cardiotoxicity, which is believed to be mediated by oxidative stress and complex interactions with iron. However, the relationship between iron and DOX-induced cardiotoxicity remains controversial and the role of iron chelation therapy to prevent cardiotoxicity is called into question. Firstly, we evaluated in vitro the effects of DOX in combination with dextran-iron on cell viability in cultured H9c2 cardiomyocytes and EMT-6 cancer cells. Secondly, we used an in vivo murine model of iron overloading (IO) in which male C57BL/6 mice received a daily intra-peritoneal injection of dextran-iron (15mg/kg) for 3weeks (D0-D20) and then (D21) a single su…
Dexamethasone upregulates Nox1 expression in vascular smooth muscle cells.
2014
<b><i>Background/Aim:</i></b> It has been demonstrated that dexamethasone-induced hypertension can be prevented by the NADPH oxidase inhibitor apocynin. The effect of dexamethasone on NADPH oxidase, however, is unknown. The present study was conducted to investigate the effect of dexamethasone on the gene expression of Nox1, the major NADPH oxidase isoform in vascular smooth muscle cells. <b><i>Results:</i></b> Oral treatment of Wistar-Kyoto rats with dexamethasone (0.03 mg/kg/day) for 12 days led to an upregulation of Nox1 mRNA expression in the aorta. In cultured A7r5 rat aortic smooth muscle cells, dexamethasone increased Nox1 mRNA expressi…
Fludarabine prevents smooth muscle proliferation in vitro and neointimal hyperplasia in vivo through specific inhibition of STAT-1 activation.
2007
Drug-eluting stents are increasingly used to reduce in-stent restenosis and adverse cardiac events after percutaneous coronary interventions. However, the race for the ideal drug-eluting stent is still on, with special regard to the best stent-coating system and the most effective and less toxic drug. Fludarabine, a nucleoside analog, has both anti-inflammatory and antiproliferative cellular effects. The aim of the present study was to assess the cellular and molecular effects of fludarabine on vascular smooth muscle cell (VSMC) growth in vitro and in vivo and the feasibility and efficacy of a fludarabine-eluting stent. To study the biomolecular effects of fludarabine on VSMC proliferation…