Sodium transport and sodium distribution in the frog skin epithelium
Govardovskij, V.I.; Allakhverdov, B.L.; Burovina, I.V.; Natochin, Y.V.
Folia Morphologica 24(3): 277-283
1976
ISSN/ISBN: 0015-5640 PMID: 1085736 Document Number: 106006
Na distribution in the frog skin epithelium was studied by means of Komnick's pyroantimonate electron cytochemical method and by X-ray microanalysis [XRM]. Na concentration within the inner epithelial layers, i.e., stratum granulosum, stratum spinosum and stratum germinativum, bathed outside by normal Ringer solution is relatively high and constant. Substitution of the external Ringer solution with distilled water or the addition of a 10-5-10-7 M solution of triamterene or amiloride, markedly decreased Na concentration within the cells of stratum granulosum. Short-circuiting resulted in the swelling of these cells. The swollen intracellular regions contained many pyroantimonate granules. Ouabain increased the Na concentration throughout the epithelial layers except the cornified cells. XRM of freeze-dried, Epon-embedded skins corroborated the electron cytochemical results. The data obtained were in line with Ussing's model of the transepithelial transport. The Na moved across the cells and the transporting cells were those of stratum granulosum.