OBJECTIVE To assess the value of dobutamine over dipyridamole as a pharmacological stressing agent in myocardial perfusion imaging with thallium-201. DESIGN Stress and redistribution tomographic images were taken in a group of patients in a randomised crossover study of both agents. The scans were scored to give a value for the stress and redistribution images and a reversibility score (redis...

BACKGROUND The traditional method to determine the binding sites of inhibitors bound to nucleoside transporters on cell membrane is the radioactive assay. This method suffers from radiolabel instability and the need to dispose of reactive materials. Fluorescence spectroscopy has been increasingly applied to biochemical analysis due to its high sensitivity and selectivity. We describe fluorescen...

OBJECTIVE To test the antioxidant effect of therapeutic doses of dipyridamole on cellular membranes, human erythrocytes were chosen as an appropriate model to study oxidative stress induced by cumene hydroperoxide because of their high content in heme-Fe(2+). METHODS The oxidative stress was induced by incubation with 160 micromoll(-1) cumene hydroperoxide and expressed by three main factors:...

Exogenous adenosine has been shown to have potent electrophysiologic effects and antiarrhythmic properties within the atrioventricular (AV) node. Endogenous adenosine, a nucleoside with an increased release signaled by ischemia and hypoxia, is not believed to exert significant effects during homeostatic conditions. Recent experimental evidence suggests, however, that under normoxic conditions, ...

Dipyridamole 201Tl imaging is an accepted diagnostic procedure for the evaluation of patients unable to perform adequate treadmill exercise, but is limited by high infradiaphragmatic activity. While recent studies have shown that the addition of exercise reduces this activity, the amount of exercise needed to effect such an improvement is uncertain. To prospectively evaluate the amount of walki...

Introduction: We aimed to assess whether the vasodilator effect of oral dipyridamole on the left ventricular systolic function in patients with suspected CAD is different from that of intravenous (IV) dipyridamole using Tc-99m MIBI myocardial perfusion gated SPECT. Methods: Eighty-nine patients (17 male, 72 female; 61±10 years) were enrolled in this study. The patients underwent a dipyridamole ...

BACKGROUND Many studies have shown that coronary flow reserve is reduced in patients with chest pain and angiographically normal coronary arteries. The methods used to assess coronary blood flow have varied, but in nearly all reports dipyridamole has been used to bring about vasodilatation. This study was designed to assess whether the apparent impairment of coronary flow reserve seen with dipy...

Background. Coronary vasodilator reserve is reduced in some patients with a history of chest pain and angiographically normal coronary arteries. ECG changes suggestive of myocardial ischemia during exercise also can be demonstrated in a subset of these patients. Methods and Results. We have investigated the correlation between coronary vasodilator reserve, assessed with "N-labeled ammonia and p...

T he use of vasodilator thallium-201 myocardial imaging, although still investigational, is finding wide application. The principle of vasodilator thallium-201 myocar-dial imaging was first put forward by Strauss and Pitt,' who used dimethyladenosine in dogs with experimental coronary artery narrowing. They demonstrated that dimethyladenosine increased coronary blood flow and thallium-201 uptak...