[The participation of sodium and chlorine ions in the reactions of the secretory cells and alveolar myoepithelium of the mammary gland].

The MP levels of the mammary gland's secretory cells and transepithelial differences of potential were found to depend on extracellular ions of sodium and chloride in lactating white mice. Substitution of the sodium ions with the choline ions increased a little the difference of potentials, whereas substitution of the chloride ions with sulfuric acid ions decreased it. Transepithelial electrical resistance increased in both cases. Substitution of the sodium ions with ions of choline and of the chloride ions with sulfuric acid ions suppressed hyperpolarization changes of the MP and increased the transepithelial difference of potentials. Contractile responses of myoepithelial cells to the action of acetylcholine and oxytocin were also depressed. The sodium and chloride ions seem to affect simultaneously the processes of the potassium ions release from secretory cells and contractile responses of the alveoli's myoepithelial cells.