cpu0213 and Heart-Failure

Cardiac injury induced by isoprenaline produces stress. This stress can be mediated by the activated endothelin and leptin pathway; thus, the endothelin receptor antagonist CPU0213 may reverse these changes. CPU0213 is metabolized mainly by cytochrome P450 (CYP)3A, thus, erythromycin, an inhibitor of CYP3A, could affect its effects by raising its plasma levels.. Forty rats were divided into five groups. Group 1 rats were normal. Group 2 rats were administered isoprenaline (1 mg/kg, s.c.) for 10 days. Groups 3, 4 and 5 were administered isoprenaline, but group 3 was given erythromycin (100 mg/kg, p.o.) alone on days six to ten, group 4 was given CPU0213 20 mg/kg (s.c.) on days six to ten, whilst group 5 received erythromycin plus CPU0213 on days six to ten. Measurements were conducted to observe changes in the haemodynamics, cardiac weight index, serum lactate dehydrogenase and creatine kinase levels, and expression of endothelin receptor A (ETA), leptin and its OBRb receptor.. In isoprenaline-treated rats, cardiac hypertrophy and dysfunction were found. This was associated with upregulated myocardial leptin protein and OBRb receptor mRNA. Immunohistochemical assay of ETA was upregulated, accompanied with downregulation of FKBP12.6 (calstabin 2) in isoprenaline-treated rats. These effects were significantly reversed by CPU0213. HPLC assay presented an increased plasma level of CPU0213 by erythromycin, but no change in its effects.. CPU0213 improved isoprenaline-induced cardiomyopathy by modulating ETA, leptin and FKBP12.6. However, erythromycin increased plasma levels but did not change its effects.

Topics: Animals; Cardiomegaly; Chromatography, High Pressure Liquid; Cytochrome P-450 CYP3A; Cytochrome P-450 CYP3A Inhibitors; Down-Regulation; Endothelin Receptor Antagonists; Erythromycin; Heart Failure; Hemodynamics; Isoproterenol; Leptin; Male; Pyrazoles; Rats; Rats, Sprague-Dawley; Receptors, Endothelin; Reverse Transcriptase Polymerase Chain Reaction; Tacrolimus Binding Proteins; Up-Regulation

Downregulation of FKBP12.6 and sarcoplasmic reticulum Ca(2+) ATPase (SERCA2a) contributes to sudden cardiac death and heart failure. We aimed to test the hypothesis that (i) downregulation of FKBP12.6 and SERCA2a can be taken as molecular markers for drug interventions and (ii) such downregulation is produced by crosstalk between endothelin-reactive oxygen species and beta-adrenoceptors stimulation, mediated by hyperphosphorylation of protein kinase Cvarepsilon (PKCvarepsilon). Rat cardiomyocytes were incubated with isoproterenol (1 microM), endothelin-1 (0.1 microM) or hydrogen peroxide (10 microM) for 18 h, resulting in downregulation of mRNA and protein of FKBP12.6 and SERCA2a, as well as upregulation of PKCvarepsilon mRNA and phosphorylated PKCvarepsilon protein. These changes were reversed by an application of either propranolol (1 microM), endothelin receptor antagonist CPU0213 (1 microM) or vitamin E (1 microM). As indicated by the fluorescent dye Fluo3, diastolic [Ca(2+)](i) in rat ventricular myocytes was increased after incubation with isoproterenol (0.1 microM). The increased [Ca(2+)](i) in diastole was dramatically decreased by CPU0213. Thus, the downregulation of FKBP12.6 and SERCA2a, and hyperphosphorylation of PKCvarepsilon, appear to be related to crosstalk between over-activated endothelin-reactive oxygen species and a beta-adrenoceptor pathway. CPU0213 is beneficial in treating cardiac insufficiency and preventing cardiac arrhythmias possibly by normalizing hyperphosphorylation of PKCvarepsilon and abnormal FKBP12.6 and SERCA2a. The antioxidant activity of vitamin E was sufficient to normalize the levels of FKBP12.6 and SERCA2a and phosphorylation of PKCvarepsilon. Thus by testing with biomarkers FKBP12.6 and SERCA2a, we have shown that the endothelin receptor antagonist CPU0213 and the antioxidant vitamin E may relieve risk of lethal arrhythmias and heart failure by suppressing PKCvarepsilon.

Topics: Animals; Antioxidants; Biomarkers, Pharmacological; Calcium; Death, Sudden, Cardiac; Down-Regulation; Endothelin Receptor Antagonists; Gene Expression Regulation; Heart Failure; Myocytes, Cardiac; Phosphorylation; Protein Kinase C-epsilon; Pyrazoles; Rats; Rats, Sprague-Dawley; Sarcoplasmic Reticulum Calcium-Transporting ATPases; Tacrolimus Binding Proteins; Vitamin E

Heart failure (HF) may be produced by sustained beta-adrenoceptor stimulation by causing changes in the expression of endothelin-1 (ET-1), the leptin system, calcineurin and sarcoplasmic reticulum Ca2+ ATPase 2a (SERCA2a) underlying cardiac dysfunction. The aim of this study was to verify whether isoprenaline (ISO)-induced HF is attributed to changes in the above molecular markers, and whether the dual ET-receptor antagonist CPU0213 could reverse the cardiac dysfunction caused by ISO treatment, focusing on these molecular markers. HF was induced in rats by administration of ISO (2 mgkg(-1) s.c.) for 10 days. CPU0213 (30 mgkg(-1) s.c.) and propranolol (4 mgkg(-1) s.c.) were administered on days 7-10. HF developed after 10 days' ISO administration and was manifest as impaired cardiac performance, increased heart weight index, oxidative stress, elevated serum enzymes, and disordered expression of the endothelin system, leptin system, calcineurin and SERCA2a. All these abnormalities were significantly reversed by CPU0213, and the effectiveness of this ET-receptor antagonist was comparable to that of propranolol. Thus, antagonism of ET receptors by CPU0213 normalizes these changes in molecular markers, alleviating HF.

Topics: Animals; Calcineurin; Cardiotonic Agents; Disease Models, Animal; Endothelin Receptor Antagonists; Endothelin-1; Gene Expression Regulation; Heart Failure; Isoproterenol; Leptin; Male; Propranolol; Pyrazoles; Rats; Rats, Sprague-Dawley; Sarcoplasmic Reticulum Calcium-Transporting ATPases

Acute heart failure (AHF) critically affects morbidity and mortality in patients suffering from septic shock. It is hypothesized that AHF is linked to down-regulation of FKBP12.6 (calstabin 2) and SERCA2a (sarco/endoplasmic reticulum Ca2+ ATPase 2a), which may be mediated by an activated endothelin (ET) system in the myocardium. The aim of the study was to test whether an attenuation of septic AHF can be achieved by a novel dual endothelin receptor antagonist, CPU0213, in association with up-regulation of FKBP12.6 and SERCA2a in rats. AHF in septic shock was produced by faeces leak from a surgically punctured caecum for 72 h in rats. CPU0213 (30 mg kg(-1), s.c., every 12 h, for 3 days) was administered to rats 8 h after the operation. In the untreated model group, survival rate markedly decreased (P < 0.01), and the cardiac performance was seriously compromised (P < 0.01) relative to control. The AHF was characteristically associated with down-regulated mRNA and protein expressions of FKBP12.6, SERCA2a and PLB (phospholamban). Elevated ET-1 and mRNA abundances of the preproET-1, ECE (endothelin converting enzyme) and ET(A) and ET(B) receptors in the left ventricular tissue (P < 0.01) were found. All abnormalities were reversed significantly following CPU0213 administration. In conclusion, septic AHF is attributed to down-regulation of FKBP12.6 and SERCA2a, which is related to an activated ET system. An endothelin receptor antagonism of CPU0213 significantly improves the cardiac performance by blocking both ET(A) and ET(B) receptors.

Topics: Acute Disease; Animals; Aspartic Acid Endopeptidases; Blotting, Western; Calcium; Calcium-Binding Proteins; Down-Regulation; Endothelin Receptor Antagonists; Endothelin-Converting Enzymes; Heart Failure; Heart Rate; Male; Metalloendopeptidases; Nitric Oxide; Nitric Oxide Synthase Type II; Oxidative Stress; Pyrazoles; Rats; Rats, Wistar; Receptors, Endothelin; RNA, Messenger; Sarcoplasmic Reticulum Calcium-Transporting ATPases; Shock, Septic; Signal Transduction; Tacrolimus Binding Proteins; Up-Regulation; Vasoconstrictor Agents

The downregulation of phospholamban (PLB) and FKBP12.6 as a result of beta- receptor activation is involved in the pathway(s) of congestive heart failure. We hypothesized that the endothelin (ET)-1 system may link to downregulated PLB and FKBP12.6.. Rats were subjected to ischemia/reperfusion (I/R) to cause heart failure (HF). 1 mg/kg isoproterenol (ISO) was injected subcutaneously (sc) for 10 d to worsen HF. 30 mg/kg CPU0213 (sc), a dual ET receptor (ETAR/ETBR) antagonist was given from d 6 to d 10. On d 11, cardiac function was assessed together with the determination of mRNA levels of ryanodine receptor 2, calstabin-2 (FKBP12.6), PLB, and sarcoplasmic reticulum Ca2+-ATPase. Isolated adult rat ventricular myocytes were incubated with ISO at 1X10(-6) mol/L to set up an in vitro model of HF. Propranolol (PRO), CPU0213, and darusentan (DAR, an ETAR antagonist) were incubated with cardiomyocytes at 1X10(-5) mol/L or 1X10(-6) mol/L in the presence of ISO (1X10(-6) mol/L). Immunocytochemistry and Western blotting were applied for measuring the protein levels of PLB and FKBP12.6.. The worsened hemodynamics produced by I/R were exacerbated by ISO pretreatment. The significant downregulation of the gene expression of PLB and FKBP12.6 and worsened cardiac function by ISO were reversed by CPU0213. In vitro ISO 1X10(-6) mol/L produced a sharp decline of PLB and FKBP12.6 proteins relative to the control. The downregulation of the protein expression was significantly reversed by the ET receptor antagonist CPU0213 or DAR, comparable to that achieved by PRO.. This study demonstrates a role of ET in mediating the downregulation of the cardiac Ca2+-handling protein by ISO.

Topics: Adrenergic beta-Agonists; Animals; Calcium-Binding Proteins; Cells, Cultured; Down-Regulation; Endothelin Receptor Antagonists; Heart; Heart Failure; Isoproterenol; Male; Myocytes, Cardiac; Pyrazoles; Rats; Rats, Sprague-Dawley; RNA, Messenger; Tacrolimus Binding Proteins; Ventricular Fibrillation