Ultrastructural signs of myocardial damage due to acute experimental intoxication with ethylene glycol

The authors carried out ultrastructural studies of the myocardial sections from inbred Wistar rats in the course of acute experimental poisoning with ethylene glycol. It was shown that slight mitochondrial swelling with clearing of the matrix, myofibrillar edema with decreased electron density of the sarcoplasma and widening of channels of the smooth intraplasmatic reticulum were visible as early as at 12 hours after intoxication with no changes in light microscopy. The changes were located mainly in the subendocardial layer of the ventricles and papillary muscles. At later stages of the experimental ultrastructural changes markedly progressed. Mitochondrial swelling enhanced with destruction of mitochondrial crests, myelin-like figures formed, myofibrillar necrosis and contraction bands developed and segmental or complete dissection of the intercalated disk edges appeared. The chages were scattered all over the myocardium predominating in the subendocardial layer and papillary muscles.