Background. Adenosine attenuates f-adrenoceptor-mediated inotropic responses through GTP-binding protein in vitro. The goal of the present study was to test the hypothesis that endogenous adenosine released from the ischemic myocardium blunts the inotropic response to /3-adrenergic stimulation. Methods and Results. In 45 open-chest dogs, the left anterior descending coronary artery was perfused...

Cardiogenic shock is associated with substantial morbidity and mortality. Although inotropic support a mainstay of medical therapy for cardiogenic shock, little evidence exists to guide the selection agents in clinical practice.

In a preceding paper, we employed an initially spherical, modified membrane model of the infarcted ventricle to investigate the relation between ventricular function and both infarct size and infarct stiffness. In the present paper, we have applied the same model to a set of different questions, namely, the consequences of enhanced or depressed inotropic state within the noninfarcted myocardium...

Peripheral vascular effects of opioid peptides are well known, but direct myocardial effects have not been established. We studied the inotropic response of spontaneously beating cultured chick embryo ventricular cells to the enkephalin analogue [D-Ala2]-enkephalin. Amplitude of cell motion increased in a concentration-dependent manner with 0.53 microM [D-Ala2]-enkephalin producing half-maximal...

Although ATP, acting through a P2 purinoceptor, can stimulate a pronounced positive inotropic effect in cardiac ventricular myocytes, the receptor-effector mechanism that underlies this stimulatory cardiac action is not well understood. The objectives of the present study were to develop the cultured chick embryo ventricular myocytes as a novel model for the cardiac P2 purinoceptor and to deter...

The potential functional roles of M(3) muscarinic receptors in mouse atria were examined by pharmacological and molecular biological techniques, using wild-type mice, muscarinic M(2) or M(3) receptor single knockout (M(2)KO, M(3)KO), and M(2) and M(3) muscarinic receptor double knockout mice (M(2)/M(3)KO). Real-time quantitative reverse transcriptase-polymerase chain reaction analysis showed th...

Although there is increasing recognition that all inotropic agents are not alike, they continue to be viewed in the generic sense because of the lack of a classification system. Analogous to the classification system proposed for the antiarrhythmic agents over 20 years ago, a classification system is proposed that categorizes inotropic agents according to their mechanisms of action. Agents are ...

The appropriateness of inotropic therapy in chronic heart failure was examined by critically reviewing five assumptions upon which this form of therapy has been justified. Only the first, that cardiac performance can be acutely improved by inotropic therapy, has been empirically proven. That such acute improvement is sustained appears to be true with non-catecholamine agents whereas the chronic...

for geriatric patients. The negative inotropic effect of sympathomimetic amines has scarcely been reported in rature. Wenzel and Su (3), while studying the interactions of sympathomimetic amines with ir antagonists on isolated rat ventricular strips, observed that phenylephrine initially produceda negative inotropic effect which was later on followed by usual positive inotropic response. imilar...