Morphological study of acute myocardial lesions experimentally induced by methamphetamine.

Abstract

A single intraperitoneal injection of methamphetamine hydrochloride (10 mg/kg) given to rats in a warm (30 degrees C) and humid environment caused an uncommon form of cardiac lesion during the first few hours. Disseminated loss of myoglobin was demonstrated immunohistochemically in the ventricular myocardium. Ultrastructurally, the myocardial cells with myoglobin loss were characterized by the presence of swollen mitochondrial and packed cellular constituents, but showed no cytoplasmic edema. Sarcolemmal damage was also noted by freeze-fracture electron microscopy. It was considered that the mitochondrial dysfunction was the first alteration to appear in the myocardial cells, and that this finally led to sarcolemmal rupture.