[Effect of the ionic composition of the environment on the intracellular potential of the alga Acetabularia].

Concentration of K+-, Na+-, Mg++-, Ca++-, Cl-ions defined in Acetabularia crenulata cell was the same as that of Acetabularia mediterranea, both were cultivated under the same conditions. At the variations of the ionic composition of the external medium it has been shown that the potential of Acetabularia (A.) cell depends on K+-, Cl-ions and alga A. can accumulate K+- Cl-ions and lose Na+, Mg++ ones when there is a deficiency of these ions in the medium. Na+-, Mg++-ions participation in the generation of the rest potential of Alga A. is insignificant. K+- ion is able to change the ionic permeability of the membrane. There is a possibility of the existance of essential H+-, -OH-, or HCO3- ions flux in A. cell.