MYOCARDIAL-INFARCTION AND PURINE TRANSPORT INHIBITION IN ANESTHETIZEDFERRETS

The potential cytoprotective effect of the purine transport inhibitor S-(p-nitrobenzyl)-6-thioinosine (NBTI) in a model of myocardial ischae mia and reperfusion was investigated in the anaesthetised ferret. The left anterior descending coronary artery (LAD) was occluded for 90 min , producing ischaemia in 53 +/- 3% of the left ventricular free wall, followed by 240 min reperfusion. NBTI (0.5 mg kg(-1), i.v.) was given prior to ischaemia or prior to reperfusion. In addition the effect of purine transport inhibition was investigated in animals subjected to i schaemia without reperfusion. NBTI reduced infarct size from 84.0 +/- 1.7 to 71.4 +/- 3.7% of the area at risk (P < 0.05) when given prior t o occlusion of the LAD. NBTI was ineffective however when given 15 min prior to reperfusion. NBTI had no effect upon infarct size produced b y ischaemia without reperfusion. The effect of NBTI was independent of significant changes in myocardial blood flow during ischaemia and rep erfusion or upon neutrophil infiltration.