introduction: it was shown in a previous study, that mcpip, a cilostamide derivative, increased atrial contraction force without changing contraction rate. to improve this property, two new derivatives of cilostamide were synthesized and their effects on pde3 activity and isolated rat atria contraction were investigated. methods: the inhibitory effect of each compound on pde3 enzyme was determi...

Objective(s): Recently, we showed that some new synthetic compounds structurally related to cilostamide (4-(1,2-dihydro-2-oxoquinolin-6-hydroxy)- N-cyclohexyl-N-methylbutanamide), a selective phosphodiesterase 3 (PDE3) inhibitor, produce inotropic effect comparable to that of IBMX (3-isobutyl-1-methylxanthine), a non-selective PDE inhibitor, but with differential chronotropic effect. In this in...

a,-Adrenoceptor stimulation of rat left ventricular papillary muscles by phenylephrine in the presence of propranolol resulted in rapid breakdown of phosphatidylinositol 4,5-bisphosphate (PI-4,5-Pj) and a triphasic inotropic response in a concentration-dependent manner. The release of inositol trisphosphate (IP,) was maximum within 30 seconds and remained high for at least 30 minutes. The IP3 f...

myocardial dysfunction is a major complication in cardiac surgery that needs inotropic support. this study evaluates the effect of milrinone on patients with low ventricular ejection fraction undergoing off- pump coronary artery bypass graft (opcab). the present study is designed to evaluate the effect of milrinone on myocardial dysfunction. eighty patients with low ventricular ejection fractio...

alpha 1-Adrenoceptor stimulation of rat left ventricular papillary muscles by phenylephrine in the presence of propranolol resulted in rapid breakdown of phosphatidylinositol 4,5-bisphosphate (PI-4,5-P2) and a triphasic inotropic response in a concentration-dependent manner. The release of inositol trisphosphate (IP3) was maximum within 30 seconds and remained high for at least 30 minutes. The ...

The purpose of our study was to investigate the inotropic response to the endogenous agonist norepinephrine mediated through alpha-1 adrenoceptors and to compare this response to that mediated through beta-adrenoceptors in failing human ventricular myocardium. We studied ex vivo the inotropic effect of norepinephrine in isometrically contracting trabecular myocardium from both ventricles of exp...

Although the positive inotropic effect of cardiac glycosides correlates well with inhibition of Na+ pump activity in many preparations, digitalis at low concentrations (10(-9) to 10(-8) M) may produce an apparent stimulation of monovalent cation transport in isolated intact myocardium or produce an inotropic effect that does not correlate with pump inhibition. Digitalis is known to modify tissu...

We studied the effect of vagal afferents on the left ventricular contractile response (LVdP/dtmax) to administration of sympathomimetic amines into the left circumflex coronary artery in conscious dogs. The positive inotropic effects of bolus administration of epinephrine, norepinephrine, and isoproterenol were greater during bilateral vagal cold block (BVB) that in the control state with the v...

In blood-perfused isolated canine atrium preparations, single injections of dibutyryl cyclic AMP at a dose range of 1 to 30 mg were made into the cannulated sinus node artery. At doses above 3 mg, dibutyryl cyclic AMP induced a biphasic chronotropic and inotropic response; there was a slight and rapid negative chronotropic and inotropic response, followed by a long-lasting positive chronotropic...