The metabolic effects of glucagon on the heart were studied in subjects with and without coronary artery disease. In both groups, a moderate rise in the arterial glucose level occurred with practically unchanged glucose uptake by the myocardium. Myocardial oxygen extraction was also unchanged in both groups of subjects. In individuals with normal coronary arteries, myocardial extraction ratio o...

Intravenous infusion of L-glutamic acid results in the augmentation of the cardiac output and an improvement of the circulation in patients with postoperative cardiac failure. This effect is not accompanied by increased myocardial oxygen demand. Arterial plasma glutamate level rises 10-fold and arterial-coronary sinus plasma glutamate difference increases fivefold during intravenous L-glutamic ...

The effects of diabetes on myocardial metabolism are complex in that they are tied to the systemic metabolic abnormalities of the disease (hyperglycemia and elevated levels of free fatty acid and ketone bodies), and changes in cardiomyocyte phenotype (e.g., down-regulation of glucose transporters and PDH activity). The cardiac adaptations appear to be driven by the severity of the systemic abno...

Background Simultaneous acquisition PET-MRI is a new technology that has the potential to significantly impact diagnostic patient care. Cardiac imaging using PET-MRI offers high signal resolution MRI images superimposed on PET metabolic functional assessment. Specifically, 18Ffluorodeoxyglucose (FDG) PET-MR has the potential to provide both anatomic scar tissue evaluation and information regard...

A significant release of catecholamines within the heart has been observed during myocardial ischemia. Because this can be markedly inhibited by amine-uptake-blocking agents, it has been suggested that its mechanism is a carrier-mediated efflux from neurons, which is not operative under normal conditions. The present work examined this release process in chromaffin cells isolated from the bovin...

A significant release of catecholamines within the heart has been observed during myocardial ischemia. Because this can be markedly inhibited by amine-uptake-blocking agents, it has been suggested that its mechanism is a carrier-mediated efflux from neurons, which is not operative under normal conditions. The present work examined this release process in chromaffin cells isolated from the bovin...

the worldwide prevalence of insulin resistant states such as the metabolic syndrome has grown rapidly over the past few decades. the metabolic syndrome is a constellation of common metabolic disorders that promote the development of atherosclerosis and cardiovascular disease. studies in both human and animal models suggest that hepatic inflammation and insulin resistance are key initiating fact...

Although thallium-201 exercise scintigraphy has been established for the detection of myocardial ischemia and viability, little is known regarding the myocardial thallium-201 kinetics during angioplasty. Herein, we report a 77-year old man with angina pectoris, in whom serial myocardial imaging after a single dose of thallium-201 was helpful in identifying not only the culprit lesion and myocar...

I n type 2 diabetes, heart muscle is insulin resistant. Protein kinase B (PKB)/Akt) acts as a mediator of the metabolic effects of insulin, including translocation of the insulin sensitive glucose transporter, GLUT4, in a manner dependent on phosphatidylinositol-3-kinase (PI-3-K). We have previously described dysregulation of PKB/Akt in hearts from a rat model of type 2 diabetes, the Zucker fa/...

We have previously demonstrated reduced myocardial glucose uptake rates in hearts of endurance athletes, which could be due to increased use of alternative fuels or reduced energy demands. In the present study myocardial blood flow, oxygen consumption, and free fatty acid uptake were measured with [15O]H2O, [15O]O2, [18F]FTHA, and positron emission tomography (PET) in 9 endurance athletes and 1...