THE behavior of excitable cells like those in muscles and nerves, of secretory cells like those in the kidney or gastrointestinal tract, and indeed of all the body's cells, whatever their function, depends critically on the electrical potential across their plasma membranes. Because this is largely determined by the ratio of intracellular to extracellular potassium (and therefore in a practical sense, chiefly by the extracellular potassium concentration), a number of biologic mechanisms have evolved to regulate the concentration of potassium in serum. Renal excretion is a dominating influence in adjusting the daily external potassium balance. But extrarenal devices1, 2 must be.
ASJC Scopus subject areas