Electron microscopic study of rat myocardial infarcts induced by a free radical generator system

Abstract

The role of oxygen free radicals in the development of tissue injury and necrosis, including myocardial ischemic damage, is well documented. In this investigation, application of a free radical generator system (FRG) to rat myocardium resulted in ECG alterations typical of myocardial infarction; 24 hours after treatment, plasma lactate dehydrogenase (LDH) levels were elevated and 20% of the left ventricle was infarcted. In order to characterize the type of cellular damage and the ultrastructural changes in the affected cells, myocardial infarcts and myocardium from control rats were examined in the electron microscope.Six spontaneously hypertensive rats were lightly anesthetized with sodium pentobarbital and infused for 10 minutes through a carotid cannula near the ostium of the coronary artery. Three rats were infused with a FRG consisting of purine (2.3 mM), xanthine oxidase (0.02 μ/ml), and Fe -loaded transferrin (0.06 μM), and 3 sham-operated rats served as controls.