The localization of sodium in the teleost cornea.

T.he localization of sodium in the avian salt gland by means of an electron-dense precipitate of sodium pyroantimonate was first used by Komnick and Komnick. Recently, Kaye and associates utilized this method to localize sodium in rabbit corneal endothelial cells—normal and ouabain treated. Zadunaisky used modifications of this method to locate the specific sites of sodium ion in the membranous system of skeletal muscle. Hartmann also applied this sodium specific stain to localize sodium ion in cells of the cerebral cortex. To verify the precipitate as sodium pyroantimonate, Hartmann utilized electron diffraction procedures. The fresh water teleost cornea is impermeable to sodium ion and has a low order of water movement from epithelium to endothelium, despite the presence of an osmotic gradient which favors water movement into the cornea and sodium movement out of it. In adapting to its aquatic environment, the teleost has maintained a high total corneal sodium content. The