Erythrocyte Membrane: Structure, Function, and Pathophysiology

Erythrocytes are unique among mammalian cells. They contain no nucleus or subcellular metabolic structures, yet they survive for 3 to 7 rn~nths .~ ' During their lifetime, erythrocytes travel thousands of miles through tubes of various sizes while delivering oxygen to the tissues.2o Survival of practically all other cells in the body depends upon the proper functioning of erythrocytes. They travel as individual cells, containing a concentrated solution of hemoglobin surrounded by a membrane. In spite of their apparent simplicity, they have limited (but necessary) metabolic capability. They are exposed to a high oxygen content and come in contact with a variety of endogenous and exogenous chemicals. Their ability to survive depends on the ability of the membrane to remain intact and flexible.20 This paper focuses on the erythrocyte membrane structure and function and the pathophysiological changes that can occur when the membrane is exposed to an unfavorable environment.