[Changes in membrane potential and cell volume of Balb C mice T lymphocytes in different physiological conditions in media with different content of D2O].

It is shown that the changes in membrane potential of thymocytes in aqueous medium with a definite D2O concentration are due to changes in the Na/K-ATPase activity. Low D2O concentrations activate whereas high concentrations inhibit the enzymatic reaction. The experimental data obtained suggest the discreteness of functionally active conformations of the enzyme.