Learn More
A method has been developed for culturing cardiac myocytes in a collagen matrix to produce a coherently contracting 3-dimensional model heart tissue that allows direct measurement of isometric contractile force. Embryonic chick cardiomyocytes were mixed with collagen solution and allowed to gel between two Velcro-coated glass tubes. During culture, the(More)
(1) This study was performed to elucidate the relation between positive inotropy and phosphodiesterase inhibition in the heart. Therefore, the influence on the activity of guinea-pig cardiac phosphodiesterase (PDE) I–III separated by DEAE-cellulose anion exchange chromatography was investigated for the new cardiotonic agents pimobendan, its metabolite UD-CG(More)
The contractile response and myocardial content of Gi-proteins were examined in cardiac preparations from explanted hearts of four different patients with end-stage heart failure. Three patients had idiopathic dilated cardiomyopathy and one patient had inflammatory heart disease. Preparations from patients with idiopathic dilated cardiomyopathy showed(More)
Adenosine added to isolated electrically driven preparations of human ventricular heart muscle antagonized the positive inotropic effect of isoprenaline (mean EC50 19 mumol 1(-1), n = 9). Similar effects were observed with the adenosine receptor agonist (-)-N6-phenylisopropyladenosine (mean EC50 0.5 mumol 1(-1), n = 7). These data provide functional(More)
Chronic β-adrenoceptor stimulation leads to desensitization of the myocardial adenylyl cyclase signalling pathway which includes β-adrenoceptor downregulation and upregulation of Gi-protein α-subunits. However, these investigations have mainly been done in cellular preparations. In this study we report that isoprenaline infusion in vivo leads to an increase(More)
Type 1 phosphatase activity was increased in membrane vesicles from failing human ventricles compared with non-failing controls. Likewise, expression of the mRNA encoding for type 1 phosphatase was enhanced by 37%. The present study provides evidence that alterations of phosphatase activity coincide with end-stage heart failure. Thus, enhanced activity of(More)
Okadaic acid exerts a positive inotropic effect in cardiac preparations. We studied whether the positive inotropic effect of okadaic acid in cardiac preparations could be due to phosphatase inhibition and whether this inhibition affects the phosphorylation of cardiac proteins. In papillary muscles from guinea pigs, 30 microM okadaic acid increased force of(More)
OBJECTIVES Human heart failure is associated with prolonged relaxation and prolonged Ca2+ transients which indicates an impaired function of the sarcoplasmic reticulum (SR) and may be detrimental for cardiac function. Controversy exists whether the altered SR function is accompanied by changes in the expression of phospholamban (PLB) and cardiac(More)
1. alpha 1-Adrenoceptor densities were studied in cardiac membrane preparations from several mammalian species including human failing hearts under identical experiment conditions; the alpha 1-adrenoceptor antagonist, [3H]-prazosin, was used as radioligand. End-stage heart failure (NYHA IV) in human hearts was due to idiopathic dilated cardiomyopathy. 2.(More)
Nitric oxide (NO) is an ubiquitous signaling molecule produced from L-arginine by NO synthase (NOS). In the vasculature, NO mediates parasympathetic endothelium-dependent vasodilation. NO may also mediate the parasympathetic control of myocardial function. This is supported by the observations that NOS3, the endothelial constitutive NOS, is expressed in(More)