H. Endo et al., ULTRASTRUCTURE OF CARDIAC MYOCYTES IN THE GREATER BANDICOOT RAT (BANDICOTA-INDICA), Journal of veterinary medical science, 57(3), 1995, pp. 389-393
Cardiac myocytes in the left ventricle and atrium of the greater bandi
coot rat (Bandicota indica) were examined by transmission electron mic
roscopy. The fine structure showed typical features of mammalian cardi
ac myocytes. In atrial myocytes, however, the areas occupied by mitoch
ondria were much smaller than that filled with myofibrils. The decreas
e in mitochondria and the abundance of myofibrils are thought to be an
ultrastructural adaptation to the large body size of this species. Ma
ny conducting myocytes were observed in both atrium and ventricle. The
atrial conducting myocytes were ultrastructurally :different from the
Purkinje fibers of the ventricle. We suggest that the abundance and t
he ultrastructural variation of conducting myocytes are related to the
physiological aspects, such as body size, of this animal.