OXYGEN DIFFUSION INTO CELLS

The question of diffusion of oxygen into cells, in distinction to tissues, requires examination of several factors not previously considered. The relation between external oxygen pressure and rate of respiration may be complicated by the existence of different diffusion constants and respiration rates in separate cell zones.Equations are developed covering such cases for two concentric zones in a sphere and relating rate of respiration to oxygen concentration, cell radius, and diffusion coefficient.When the assumption, made in similar studies for tissues, that consumption in any one region is independent of oxygen pressure if above zero, is avoided, the observed consumption-pressure curve can be corrected for diffusion effects to give the true consumption-pressure relation. Equations for this correction are presented.Available data on bacteria, marine eggs, and other material, are examined quantitatively. It appears very probable that oxygen consumption in each region is dependent on oxygen concentration ...