Ion Exchange Mechanisms in the Nephron

Accumnulating evidence favors the view that in biologic systems, the active transport of strong electrolytes involves coupled exchanges of ions, usually of sodium for potassium. In the present paper, the author considers the renal exchange of potassium, sodium and hydrogen in this light, and reviews current concepts concerning the mechanisms involved in the secretion of these ions by the kidney. He indicates that new investigative technics will be required to establish that the kidney behaves with respect to coupled ion exchanges as do nerves, red blood cells and frog skin. He concludes by cautioning against extrapolation of experimental results from one species to another.