The role of membrane structure and function in cellular aging: a review.

A survey of the available theoretical and experimental evidence is given regarding the cell membrane properties, such as the membrane fluidity, potassium permeability, etc., which are involved in the regulation of intracellular ion contents. These properties of the membrane undergo some age-dependent alterations in numerous cells studied so far, resulting in an increase of the intracellular potassium content. This phenomenon has a serious inhibitory effect on the rates of enzymatic catalyses involved in the protein synthesis, and may explain the decreased protein synthetic capacity of the old cells. Data are presented indicating that some changes in the membrane permeability are also involved in the malignant transformation of the cells; however, these are of opposite direction as compared to aging of cells. The "membrane hypothesis" of aging based on these facts seems to be a useful experimental approach to the problem of cellular aging.