The purpose of these studies was to test whether 02 tension influences cardiotoxicity due to doxorubicin. Isolated hearts were perfused by the method of Langendorff at constant pressure with Krebs-Henseleit buffer saturated with 5% CO2 and either 95% or 20% 02. Toxicity due to doxorubicin was evaluated from changes in heart rate and from uptake of trypan blue by nonviable nuclei. Heart rate was...

BACKGROUND Volatile anesthetics produce differing degrees of myocardial protection in animal models of ischemia. The purpose of the current investigation was to determine the influence of isoflurane and halothane on myocardial protection in a human model of simulated ischemia and the role of adenosine A1 receptors and adenosine triphosphate-sensitive potassium (KATP) channels in the anesthetic ...

Using an experimental model of ascending aortic banding in the rat, we examined whether coronary circulation abnormalities in hypertrophied hearts are reversible after debanding. 4-wk banding produced significant increases in in vivo left ventricular (LV) pressure (194 +/- 13 vs. 114 +/- 9 mmHg in shamoperated controls) and LV dry wt/body wt (48 +/- 5% above controls). In isolated hearts perfus...

Noradrenaline uptake was studied using heart muscle from 102 patients undergoing cardiac surgery. Slices of right atrium were incubated in Krebs-Henseleit solution containing 1.3 x 10(-7) M 3H-noradrenaline. Uptake was lower in failing heart muscle and was inhibited not only by increasing the noradrenaline concentration in the incubating medium but also by adding the drugs desmethylimipramine, ...

37°C. Krebs-Henseleit bicarbonate buffer solutions were added to the hemichambers on each side of the tissue: the buffer on the mucosal (lumen) side was modified such that lithium chloride replaced sodium chloride at concentrations ranging from 0 to 40 mmol/l. The extracellular marker polyethylene glycol, M, 900 (PEG-900), was also present in buffer solutions on the mucosal side of the tissue. ...

NEW FINDINGS What is the central question of this study? Rate-pressure product (RPP) is commonly used as an index of cardiac 'effort'. In canine and human hearts (which have a positive force-frequency relationship), RPP is linearly correlated with oxygen consumption and has therefore been widely adopted as a species-independent index of cardiac work. However, given that isolated rodent hearts d...

In order to study particle phagocytosis and glycogenolysis simultaneously, this study was designed to develop a direct-read-out method to monitor Kupffer-cell function continuously, based on the uptake of colloidal carbon by the isolated perfused rat liver. Livers were perfused for 20 min with Krebs-Henseleit buffer saturated with O2/CO2 (19:1). Colloidal carbon (1-2 mg/ml) was added to the buf...

The pathophysiology of human airway narrowing is only partly understood. In order to gain more insight in the mechanisms of human lung diseases and potential beneficial therapeutic agents, adequate models are needed. Animal airway models are of limited value since lung diseases such as asthma and chronic obstructive pulmonary disease (COPD) are unique to humans and because the mechanisms of air...