Background—We have recently shown that genetic inactivation of phosphoinositide 3-kinase (PI3K ), the isoform linked to G-protein–coupled receptors, results in increased cardiac contractility with no effect on basal cell size. Signaling via the G-protein–coupled -adrenergic receptors has been implicated in cardiac hypertrophy and heart failure, suggesting that PI3K might play a role in the path...

BAY y 5959 is a dihydropyridine derivative with positive inotropic actions mediated by a direct increase in intracellular calcium. We characterized the direct myocardial actions of this new agent in hearts isolated from seven normal dogs and from five dogs with repeated coronary microembolization-induced heart failure. Inotropic actions of BAY y 5959 were accompanied by little effect on duratio...

Background: Isoproterenol, a β-adrenergic agonist, may induce myocardial infarction when used in high dosage rats. This study was conducted to evaluate the effect of ethanol extract Kleinhovia hospita leaves on cardiac biomarkers and structures rats induced by isoproterenol. Methods: Male (n=30) were assigned as normal controls or treatment groups. The groups received pretreatments, either plac...

background: there are controversial reports about the exact mechanisms of lead-induced hypertension, but many factors such as alteration in the responsiveness of cardiovascular system to endogenous substances including catecholamines could be one of the mechanisms involved. in present study, the effect of exposure to 100 ppm lead acetate by drinking water (in the periods of 4, 8 and 12 weeks) o...

The present study aimed to investigate betanin ameliorates isoproterenol-induced AMI through iNOS, inflammation, oxidative stress-myeloperoxidase (MPO)/low-density lipoprotein (LDL) in rat. Cardiovascular diseases CVD is considered as the first killer of human beings. The major pathogenesis of malignant cardiovascular events is chronic heart failure caused by acute myocardial infarction (AMI). ...

BACKGROUND In heart failure, brain-type natriuretic peptide (BNP) is elevated and the sarcoplasmic reticulum Ca(2+)-ATPase (SERCA) downregulated. We previously showed that preload-induced SERCA-upregulation is suppressed by exogenous BNP. METHODS AND RESULTS Here we tested the hypothesis that afterload and neurohumoral activation would counterregulate preload-dependent SERCA upregulation thro...

Sympathetic nervous activation is a crucial compensatory mechanism in heart failure. However, excess catecholamine may induce cardiac dysfunction and beta-adrenergic desensitization. Although magnesium is known to be a cardioprotective agent, its beneficial effects on acute cardiac dysfunction remain to be elucidated. We examined the effects of magnesium on left ventricular (LV) dysfunction ind...

Several clinical trials have demonstrated that angiotensin-converting enzyme inhibitor (ACEI) and angiotensin II type 1 receptor blocker (ARB) are equally effective in the treatment of chronic heart failure. However, this has not been confirmed for acute cardiac dysfunction. We examined whether ACEI or ARB prevents isoproterenol-induced acute left ventricular (LV) dysfunction in dogs. LV dysfun...