On the Sodium and Potassium Balance of Isolated Frog Muscles

Abstract

PHYSIOLOGY: H. B. STEINBACH tween the Vo and the proton should be the same as between the neutron and the proton, at least as far as both potentials are due to the interaction with 7r mesons. Under this assumption, the scattering cross-section for the collision of Vo particles with protons or neutrons is very nearly equal to the proton-neutron scattering cross-section at the same energy. If it should be possible to measure the former cross-sections it would give a clue concerning the validity of the analogy between heavy particle conservation and charge conservation laws.

Electrical activity and intracellular sodium concentration in frog muscle

“…This behaviour has been described by Fenn & Cobb (1934), Steinbach (1940) and for frog muscle, and it has also been found in other excitable tissues. That the cation exchange is due to the displacement of some kind of equilibrium or steady state is obvious from the fact that, when transferred into a Ringer with higher potassium, the sodium-rich and potassium-depleted muscle is able to restore its original composition to an appreciable extent (Steinbach, 1940(Steinbach, , 1951. Such a soaking procedure thus provides a convenient way of altering reversibly the intracellular sodium concentration.…”

“…Accumulation of sodium in exchange for internal potassium has been brought about by prolonged soaking in a low-potassium Ringer (Fenn & Cobb, 1934), and this process proved to be satisfactorily reversible (Fig. 3) when the sodium-rich and potassium-depleted muscles were immersed into a solution with higher potassium content (Steinbach, 1940).…”

“…Recovery of sodium-rich muscle fibres The procedure used was similar to that introduced by Steinbach (1940), namely transferring the sodium-rich muscle into a Ringer with 10 mM-K at room temperature. A valuable modification seems to be the use of the Boyle & Conway solution which imitates the inorganic composition of frog plasma (D , Table 1).…”

A Hundred Years of Sodium Pumping

“…Using the then newly available radioactive 24 Na, Heppel (9) had shown that it took less than an hour for sodium in the muscles of potassium-deprived rats to equilibrate with sodium in the bathing solution. And Steinbach (10) had shown that frog muscles soaked in potassium-free Ringer's solution gradually lost potassium and gained sodium and that the exchange was reversible. Since, in the experiments of both Fenn & Cobb and of Steinbach, the movements of both potassium and sodium during the recovery phase were against the concentration gradients, and these movements were in opposite directions, it seemed to follow either that at least one species of ion can be pumped through the membrane or that much of the potassium inside the fibers is bound to molecules that are unable to penetrate the membrane and prefer potassium to sodium.…”

Stimulation of the sodium pump by azide and high internal sodium: changes in the number of pumping sites and turnover rate.

“…In this paper we describe experiments performed to explore the mechanism of action of two procedures which markedly increase Na pumping in skeletal muscle, namely the exposure to Na azide (Horowicz & Gerber, 1965) and the addition of K Ringer at room temperature to muscles previously equilibrated at 40C in a K-free Ringer (Steinbach, 1940).…”