Histological diagnosis of myocardial injury. Comparison of hematoxylin-basic fuchsin-picric acid (HBFP)-stained sections obtained during autopsy with isolated viable rat cardiac myocytes exposed to anoxia.

The light microscopic appearances in hematoxylin-basic fuchsin-picric acid (HBFP)-stained histological sections from cardiac and skeletal muscle tissue were put in relation to the reactions of isolated viable rat cardiac myocytes exposed to anoxia in suspension and their morphology in paraffin-embedded sections. Special attention was paid to prenecrotic phases of myocytic injury which were followed, in viable rat cardiac myocytes, by light microscopy, and confirmed with biochemical assays indicating increased plasma membrane permeability. In cases of sudden death, and traumatic injury to the heart and skeletal muscle, there was good agreement between alterations demonstrated with the HBFP technique and alterations of viable rat cardiac myocytes exposed to anoxia. In isolated myocytes, these alterations were associated with irregular contractility which, when occurring in situ, might have influenced the cardiac function prior to death. Moreover, the changes develop at a much faster rate than the inflammatory reaction following tissue injury and may therefore be regarded as an early vital phenomenon of significance in clinico-pathological and medico-legal considerations.