Cor pulmonale in experimental lung emphysema. II. An ultrastructure of myocardium.

Development of ultrastructural changes in the hearts of rats with experimental lung emphysema, induced by proteolytic enzyme--papain, has been analysed. Simultaneous development of changes in the right ventricle muscle and in the subendocardial layer of the heart left ventricle myocardium was observed. After 1 month from papain administration in the muscle cells of the right ventricle a significant increase of mitochondria number and their polymorphism were observed. After 3 and 6 months similar changes were observed in both ventricles, however they were more pronounced in the cells of the right ventricle. Mitochondria showed significant damage in the form of clearning up of matrix and destruction of cristas and breaking of their membranes. An enlarged number of irregular intercalated discs was observed too. 6 months after papain administration in some of the right ventricle muscle cells a significant damage of myofibrils and increase in the number of sarcomeres as well as decrease of mitochondria number in these cells were noticed. Focally proliferation of connective tissue was observed too. The role of hypoxia as an essential factor, responsible for the observed morphologic changes has been discussed.