Oxygen transport - The oxygen delivery controversy

Abstract

Most cellular activities require energy in the form of oxygen, primarily obtained from the degradation of adenosine triphosphate (ATP) and other high-energy compounds. Oxygen must be present in sufficient amounts in the mitochondria to maintain effective concentrations of ATP in the electron transport system. Cells have to perform a series of activities essential for survival, including membrane transport, growth, cellular repair and maintenance processes. In addition, cells often have facultative functions such as contractility, electrolyte or protein transport, motility and various biosynthetic activities. If oxygen availability is limited, cellular oxygen consumption may fall and become supply-dependent. Facultative functions are the first to be altered, leading to organ dysfunction. If the situation becomes more serious, obligatory functions can no longer be maintained and irreversible alterations may occur. © 2006 Springer-Verlag Berlin Heidelberg.