Adaptation to potassium

摘要

In vertebrates, the development of complex and efficient mechanisms for avoiding potassium intoxication might be predicted from a simple consideration of their chemical anatomy. The proper function of excitable membranes depends on a low concentration of potassium outside of the cell. On the other hand, potassium is the major ionic constituent of intracellular fluid; it therefore accompanies calories in almost every form of food. Animals that alternate starvation with periods of gorging themselves must therefore be able to adapt to sudden large exogenous loads of potassium in order to avoid potassium intoxication.