[Morphologic and biochemical correlations in the muscle tissue of the atria and ventricles].

Electron microscope study of the heart muscle tissue demonstrated a difference between the cardiomyocytes of the auricles and ventricles. Three varieties of cells distinguished by the character of relations between the organoids and the number of specific secretory granules in them were revealed in the muscle tissue of the auricles. In studying the activity distribution of the lactate dehydrogenase (LDH) and its isoenzymatic pattern by disc electrophoresis and isoelectric focusing, the enzymatic spectra of LDH from the auricles and ventricles were found to differ considerably.

[Secretory granules in cardiomyocytes].

The specific granules having the appearance of spherical formations of 2000-4000 A in diameter are described in the cardiocytes of the atria and ventricles of mature frogs (R. temporaria). Each granule consists of electron dense granular matrix and a membrane up to 60 A trick.