Intermitochondrial contacts are described in rat myocardiocytes. They are characterized by a maximal drawing together (or maybe fusion) of two outer mitochondrial membranes of neighbouring mitochondria, accompanied by a strong local increase in the electron density of both of the outer and inner mitochondrial membranes as well as of the intermembrane spaces. Mitochondrial contacts were shown to connect all the single mitochondria of myocardiocyte. Contacts of the mitochondrial membranes with the plasma membrane in the nexus zone are also found. Mitochondrial contacts are absent from myocardiocytes of 3-day-old rats.
