ABSTRACT
Lipofuscin, or age pigment, accumulates with age in the lysosomal vacuome of a variety of postmitotic cell types in animals belonging to widely divergent phylogenetic groups. Augmentation of iron in the culture medium markedly increased the level of lipofuscin accumulation, whereas desferrioxamine had the opposite effect. A major difficulty in elucidating the mechanism of lipofuscin formation is the inability to define chemically what actually constitutes lipofuscin. Understanding the mechanism of lipofuscinogenesis has been hampered by confusion in terminology, the purported chemical nature, as well as the methods employed for the quantification of lipofuscin. Iron is an essential element in many important metalloorganic compounds including most of the electron transfer systems involved in a variety of redox processes. Iron, an essential metal with a multitude of important functions related to redox processes, is incorporated in very stable metalloorganic compounds during transportation and storage and in the functional state.
