Basophilic degeneration of myocardium: an ultrastructural study

The basophilic degeneration of myocardial cells is frequently observed in pathology. We studied the ultrastructure of the degeneration in human myocardial samples. Thelesion varied in different regions that could be grouped in three various types. One ofthe regions seems to be the point of origin of the degeneration; mitochondrial streaks, elements of the smooth or rough sarcoplasmic reticulum, and polyribisomes are found init. All of the structures are surrounded by a substance rich in fine filaments and microvesticles. The other two regions are more compact; one is composed mainly of osmiophilic flakes and the other consists almost exclusively of filaments, some of them showinga periodicity of 200 A. The affected cells seem to be suffering from abnormal glycogen metabolism. The substance found in basophilic degeneration shows a stron similarityto the corpora amylacea and the Lafora bodies. This substance is probably a glycoprotein and seems to accumulate because of a betabolic disturbance.