Possible division of cardiac mitochondria

Publisher Website
Google Scholar
Abstract
Numerous examples of partitioned mitochondria were present in cardiac muscle cells of mice, rats, guinea pigs, and canaries. The partitions, which usually bisected the mitochondria, consisted of two parallel membranes in direct continuity with the inner mitochondrial membrane. Some of these mitochondria showed varying degrees of constriction at the level of the partitions. In many partitioned organelles, the two sets of cristae on opposite sides of the septum were positioned at right angles to one another, so that if one set was seen in profile, the other appeared en face. This arrangement of cristae simplified the detection of partitioned mitochondria even at low magnifications.The number of mitochondria and the frequency of occurrence of partitioned mitochondria were considerably enhanced in heart muscle cells of some weanling mice by feeding them the copper‐chelating agent, cuprizone. The mitochondria, both with and without partitions, were identical to those in untreated animals. Based on this and other experimental evidence, and by analogy with other organs, notably mammalian liver and insect fat body, it was concluded that partitioned cardiac mitochondria are in fact dividing.