The cellular events during the initiation and maintenance of ventricular fibrillation (VF) are poorly understood. We developed a nonischemic, isolated, perfused rabbit Langendorff preparation in which sustained VF could be induced by alternating current (AC) and which allowed changes in perfusate composition. We also used Na+-K+ pump inhibition (10 ,uM ouabain or K'-free perfusate) to induce VF...

Ischemia and reperfusion both contribute to tissue damage after myocardial infarction. Although many drugs have been shown to reduce infarct size when administered before ischemia, few have been shown to be effective when administered at reperfusion. Moreover, although it is generally accepted that a burst of reactive oxygen species (ROS) occurs at the onset of reperfusion and contributes to ti...

We evaluated the impact of donor age on the efficacy of myocardial cellular therapy for ischemic cardiomyopathy. Characteristics of smooth muscle cells (SMC), bone marrow stromal cells (MSCs), and skeletal muscle cells (SKMCs) from young, adult, and old rats were compared in vitro. Three weeks after coronary ligation, 3.5 million SMCs (n = 11) or MSCs (n = 9) from old syngenic rats or culture m...

Cardiac function and energetics in experimental renal failure in the rat (5/6 nephrectomy) have been investigated by means of an isolated perfused working heart preparation and an isometric Langendorff preparation using 31P nuclear magnetic resonance (31P NMR). 4 wk after nephrectomy cardiac output of isolated hearts perfused with Krebs-Henseleit buffer was significantly lower (P < 0.0001) at a...

OBJECTIVE (R)-2-methoxyethyl1-(1-phenylethyl)-1H-imidazole-5-carboxylate hydrochloride (ET-26 HCl) is a novel etomidate analogue. The purpose of this study was to characterize whether ET-26 HCl could retain the superior myocardial performance of etomidate in vivo and in vitro. METHODS In vivo, the influence of ET-26 HCl and etomidate on the cardiac function of dogs was confirmed using echocar...

OBJECTIVE Evasins (chemokine-binding proteins) have been shown to selectively neutralize chemokine bioactivity. We investigated the potential benefits of Evasin-3 on mouse myocardial ischemia/reperfusion injury. METHODS AND RESULTS In vivo and ex vivo (Langendorff model) left coronary artery ligature was performed in C57Bl/6 mice. Coronary occlusion was maintained for 30 minutes, followed by ...

To investigate if spontaneous ischemic events in mice with severe multi-organ atherosclerosis could adapt to ischemia, apolipoprotein E/LDL receptor knockout mice were fed an atherogenic diet for 7 to 9 months. Signs of spontaneous ischemia occurred. One to two days later, hearts were excised, Langendorff-perfused with induced global ischemia, and compared with mice without signs of disease. In...

Given the importance of lipoprotein lipase (LPL) in cardiac and vascular pathology, the objective of the present study was to investigate whether the beta-agonist isoproterenol (Iso) influences cardiac LPL. Incubation of quiescent cardiomyocytes with Iso for 60 min had no effect on basal, intracellular, or heparin-releasable (HR)-LPL activity. Similarly, Iso did not change HR-LPL in Langendorff...

BACKGROUND Apoptosis is an important cause of early graft loss after heart transplantation. Bcl-xL was reported to protect the heart against normothermic ischemia and reperfusion injury. In this study, we determined whether overexpression of Bcl-xL could inhibit tissue injury resulting from prolonged cold preservation followed by warm reperfusion of heart transplants. METHODS AND RESULTS Lewi...

This report describes a Langendorff heart preparation, which utilizes frog rather than mammalian hearts to demonstrate both mechanical and electrical events of the cardiac cycle. The preparation is durable in that it can be maintained for several hours while being perfused with room-temperature solutions that are not supplemented with oxygen. Ventricular perfusion is achieved via a fluid-filled...