MECHANISM OF THE FORMATION OF MEGAMITOCHONDRIA INDUCED BY COPPER‐CHELATING AGENTS

Abstract

Processes of the formation of cuprizone-induced megamitochondria in mouse liver have been studied in detail by electron microscopy. The earliest change observed was the presence of large intramitochondrial granules. The next stage was the formation of myelin figures by which mitochondria were apparently connected. The third stage was characterized by megamitochondria connected with each other by their outer membranes. Continuity of mitochondria were further examined by serial sections, and megamitochondria were proved to be connected to each other far more frequentlythan expected on one plane of section. A model for the mechanism of megamitochondrial formation is proposed based on electron microscopic evidences, involving the fusion of mitochondrial membranes. Possibility is also discussed that cuprizone-induced megamitochondria may fuse to one single branching mitochondrion.