Figure 8.

External Na⁺ concentration does not alter the flux ratio exponent n'. The axon was internally dialyzed with 99 mM Na⁺ and subjected to three applications of palytoxin, two at 400 mM and one at 100 mM external [Na⁺]. (A and B) Na⁺ and K⁺ composition of the superfusate. (C) Membrane potential. (D) ²²Na⁺ efflux and net membrane current. Top bars mark palytoxin treatments (solid bars; 5 nM) and ouabain exposures (hatched bars; 100 μM). The sequence of changes in the external solution composition is similar to that described for the experiment in Fig. 7. Blue and red lines have the same meaning as in previous figures.