Electron Microscopy: Sodium Localization in Normal and Ouabain-Treated Transporting Cells

Science  26 Nov 1965:
Vol. 150, Issue 3700, pp. 1167-1168
DOI: 10.1126/science.150.3700.1167


When rabbit corneas are fixed in an osmic acid fixativeto which potassium pyroantimonate has been added, an electron-opaque precipitate of sodiium pyroantimonate is localized along the cellular side of the lateral plasmla membrane of the endothelial cells. This heavy precipitate represents areas of high Na+ concentration and may represent the site of a saturated, high-affinity Na+ carrier. Significantly heavier precipitate occurs at the same site when ouabain is injected into the aqueous humor prior to fixation of the cornea.