Sodium Localization in the Plasma Membrane of the Intestinal Absorptive Epithelial Cell

Abstract

Sodium localization in the plasma membrane of the intestinal absorptive epithelial cell was demonstrated by using potassium pyroantimonate and electron microscopy.Sodium precipitates were found exclusively on the plasma membrane and were most numerous at the apical free surface of the cell.Sodium precipitates were found on the cytoplasmic side of the plasma membrane including the inner leaflet of the unit membrane.The functional significance of the finding was discussed.