Physiology and Pathophysiology of Transcellular Shift of Potassium Balance

ABSTRACT

Plasma potassium level is maintained within a narrow normal range through a transcellular shift between intracellular and extracellular space, and through renal excretion. Internal potassium balance via transcellular shift is affected by several hormones and physiologic conditions. Catecholamine through beta2-adrenergic receptor stimulates cellular uptake of potassium and defends against increments in plasma potassium concentration. Insulin promotes cellular potassium uptake in muscle, liver and adipose tissues. Changes of acid-base status affects internal potassium balance as well as renal potassium excretion. Other physiologic and pathophysiologic conditions such as exercise or tissue damage also have acute effects on the distribution of potassium. Although a lot of medications are the causes of hyperkalemia, drugs that alter internal potassium balance would appear to be uncommon. Understanding the physiology of potassium distribution is important to evaluate and manage the patients with potassium disturbances including hypokalemia or hyperkalemia.