Small concentrations of mercury enhances positive inotropic effects in the rat ventricular myocardium

2005 ◽  
Vol 20 (1) ◽  
pp. 22-25
Author(s):  
Diego Falcochio ◽  
Gabriela Poltronieri Souza de Assis ◽  
Ivanita Stefanon ◽  
Dalton Valentim Vassallo
Keyword(s):  
Ventricular Myocardium ◽  
Inotropic Effects ◽  
Positive Inotropic Effects

Atrial myocardium is the predominant inotropic target of adrenomedullin in the human heart

2007 ◽  
Vol 293 (5) ◽  
pp. H3001-H3007 ◽  
Author(s):  
Egbert Bisping ◽  
Gero Tenderich ◽  
Paul Barckhausen ◽  
Burkhard Stumme ◽  
Sebastian Bruns ◽  
...  
Keyword(s):  
Light Emission ◽  
Ventricular Myocardium ◽  
Right Atrial ◽  
Dependent Manner ◽  
Atrial Myocardium ◽  
Concentration Dependent Manner ◽  
Maximal Increase ◽  
Inotropic Effects ◽  
Positive Inotropic Effects ◽  
Camp Levels

Adrenomedullin (ADM) is an endogenous peptide with favorable hemodynamic effects in vivo. In this study, we characterized the direct functional effects of ADM in isolated preparations from human atria and ventricles. In electrically stimulated human nonfailing right atrial trabeculae, ADM (0.0001–1 μmol/l) increased force of contraction in a concentration-dependent manner, with a maximal increase by 35 ± 8% (at 1 μmol/l; P < 0.05). The positive inotropic effect was accompanied by a disproportionate increase in calcium transients assessed by aequorin light emission [by 76 ± 20%; force/light ratio (ΔF/ΔL) 0.58 ± 0.15]. In contrast, elevation of extracellular calcium (from 2.5 to 3.2 mmol/l) proportionally increased force and aequorin light emission (ΔF/ΔL 1.0 ± 0.1; P < 0.05 vs. ADM). Consistent with a cAMP-dependent mechanism, ADM (1 μmol/l) increased atrial cAMP levels by 90 ± 12%, and its inotropic effects could be blocked by the protein kinase A (PKA) inhibitor H-89. ADM also exerted positive inotropic effects in failing atrial myocardium and in nonfailing and failing ventricular myocardium. The inotropic response was significantly weaker in ventricular vs. atrial myocardium and in failing vs. nonfailing myocardium. In conclusion, ADM exerts Ca2+-dependent positive inotropic effects in human atrial and less-pronounced effects in ventricular myocardium. The inotropic effects are related to increased cAMP levels and stimulation of PKA. In heart failure, the responsiveness to ADM is reduced in atria and ventricles.

scholarly journals P4482Anticancer drug istaroxime exerts strong positive inotropic effects in failing human ventricular myocardium

2017 ◽  
Vol 38 (suppl_1) ◽  
Author(s):  
E. Kolesnik ◽  
M. Wallner ◽  
M. Khafaga ◽  
D.M. Eaton ◽  
G. Schwantzer ◽  
...  
Keyword(s):  
Ventricular Myocardium ◽  
Inotropic Effects ◽  
Positive Inotropic Effects ◽  
Human Ventricular Myocardium
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