Ultrastructure of the Ventricular Myocardium of the Bat <i>Eidolon helvum</i>

Abstract

Ultrastructural studies, including apreliminary morphometric analysis, of the right ventricular myocardium in the West African bat Eidolon helvum show that the myocytes contain a wider T-tubule system and a higher proportion of mitochondria and lipid droplets than in typical terrestrial mammals such as the rat; these features in the bat are even more pronounced than in hibernating species such as the golden hamster. In addition to having coupling arrangements with T-tubules and surface sarcolemma, cisterns of junctional sarcoplasmic reticulum are closely apposed to mitochondria and lipid droplets.

Morphometric Study of Ventricular Myocardial Cells in the Bat (<i>Pipistrellus pipistrellus</i>), Hamster (<i>Mesocricetus auratus</i>) and Wistar Rat

“…we observed that the ventricular myocardial cells are well endowed with mitochondria, lipid bodies and T tubules, compared with those of ordi nary terrestrial animals like the rat and hamster [6]. The results of the present study of ventricular myocytes of the insect-eating bat P. pipistrellus also show similar char acteristics.…”

“…3], and 450-500 nm in the hamster and seal [4. 5], Recently, differences in the cellular content of mitochon dria, myofibrils and lipid bodies of ventricular myocytes of the West African fruit-eating bat (Eidolon helvum), the hamster and the rat have also been reported [6]. The ventricularcellsofthe bat have greater concentrations of mito chondria and lipid bodies per unit volume than do those of the hamster and rat, and the cells of the hamster have greater fractional volumes of lipid bodies and T tubules compared with the myocytes of rats.…”

Ultrastructural Characteristics of Atrial, Ventricular and Subendocardial (Purkinje) Cells of the Fruit-Eating Bat <i>Eidolon helvum</i>

“…The present work is a continuation of our study examin ing the myocardial ultrastructure of the fruit-eating bat Eidolon helvum [9], The study provides further evidence of variation in mammalian cardiac cell morphology.…”

“…Although overall these organelles form 41% of the cytoplasmic volume [9], their cristae are widely spaced when compared with those of the rat and mouse. This represents a major difference in mitochondria of the fruit-eating bat and those of the insect eating bat P. pipistrellus, in which we have reported a very high density of mitochondrial cristae [2], Unlike most cardiac cells, lipid bodies are frequently seen in the matrix of mitochondria.…”

“…15 micrographs of subendocardial cells (3 from each animal) at a magnification of 25,(XX) diameters were examined. Volume fractions of similar organelles in ventricular cells of this species have been determined in a previous study [9].…”