Survival of the K+ channel in axons externally and internally perfused with K+-free media.

In perfused squid giant axons, potassium channels irreversibly deteriorate when the internal K+ is removed and replaced by impermeant ions. Under the same conditions in perfused Myxicola giant axons, the K+ conductance is also irreversibly lost with a time constant of 10-15 min. In contrast, the K+ conductance in Myxicola giant axons dialyzed with impermeant ions and bathed in monovalent cation free solutions does not deteriorate, even over 5-6 h. Thus we suggest that washout of some internal component may be an important additional factor in the deterioration of K+ channels in perfused giant axons.