[Controlled cell cultivation. IX. Dynamic study of pH changes of the medium in the pericellular area].

The dynamics of pH changes occurring near the cells has been studied after the sedimentation of cells and after the culture medium replacement. For this purpose, cells were situated on the H+-selective membrane of the electrode. The pH fall in the space hear the cells took place mainly within the first 6 hours after sedimentation or medium replacement. The magnitude of this change depends on the cell population density and reaches 1.2 units of pH, if the density value was higher than 10(6) cell/cm2. It has been shown that there are two stages in the dynamics of pH changes near the cells during the first 6 hours after sedimentation and the mean rate of pH changes depends on the cell population density. Based on the results obtained, a possibility to explain the inhibition of cell growth in the monolayer by diffuse limitations of outflowing metabolic products is discussed.