The Journal of General Physiology, Vol 44, 1131-1142,
Copyright © 1961 by The Rockefeller University Press
Na Extrusion by the Sartorius of Rana pipiens
H. Burr Steinbach 1
1 From the Department of Zoology, University of Chicago, Chicago
Sartorius muscles of R. pipiens may be enriched in sodium and depleted of potassium by prolonged soaking in the cold in K-free or low K Ringer's solution. Such K-depleted muscles take up potassium and extrude sodium when exposed to Ringer's solution containing 10 mM K at ordinary room temperature (ca. 20°C), with no dependence on external Na ion concentration in either phase within fairly wide limits.
Extrusion of excess fiber Na is demonstrated on single muscles using Na24-loaded tissues. Rate of exchange of excess fiber Na does not differ significantly from the rate of exchange of Na normally present in muscle fibers.
Submitted on December 7, 1960