Potassium and intracellular pH.

Recent work has clarified some of the complex interrelationships between cell pH and potassium. These studies have been limited by the techniques available for accurately measuring cell pH. At present it is obvious that intracellular pH is a major regulator of the cellular potassium concentration, but the precise relationship between these two is still uncertain. It has become increasingly clear, however, that no simple relationship exists between the intracellular to extracellular hydrogen ion and potassium ion ratios. Many experiments do demonstrate that the extracellular metabolic alkalosis of potassium depletion is accompanied by a decrease in skeletal muscle pH in rat, rabbit, and probably dog. The response of cardiac and renal tubular cell pH to potassium depletion is less clear, although most evidence indicates that there is also a reduction in the pH of these tissues. This effect on cell pH appears to be independent of chloride. By contrast, hyperkalemia seems to raise muscle cell pH at the same time it induces an extracellular metabolic acidosis. The metabolic and physiologic consequences of potassium-induced alterations in cell pH have yet to be fully elucidated.