Interrelationship between lipid droplets and mitochondria in brown adipocytes of the hamster

The interrelationship between lipid droplets and mitochondria in the interscapular brown adipose tissue of the hamster was investigated by electron microscopy. The membranous structure of mitochondria began to degenerate at the site in contact with lipid droplets. From that site, mitochondrial cristae also began to collapse. After being completely surrounded by lipid droplets, these degenerating mitochondria became vacuolated within them. Finally, lipid infiltrated into these vacuoles. Mitochondrion-like structures found in the lipid droplets may be possibly residues of the degenerating mitochondrial membranes.