An Integrated View of Potassium Homeostasis

The plasma potassium level is normally maintained within narrow limits by multiple mechanisms. This article reviews the mechanisms that regulate potassium homeostasis and describes the important role that the circadian clock exerts on these processes. The plasma potassium level is normally maintained within narrow limits (typically, 3.5 to 5.0 mmol per liter) by multiple mechanisms that collectively make up potassium homeostasis. Such strict regulation is essential for a broad array of vital physiologic processes, including the resting cellular-membrane potential and the propagation of action potentials in neuronal, muscular, and cardiac tissue, along with hormone secretion and action, vascular tone, systemic blood-pressure control, gastrointestinal motility, acid–base homeostasis, glucose and insulin metabolism, mineralocorticoid action, renal concentrating ability, and fluid and electrolyte balance. 1 – 3 The importance of potassium homeostasis is underscored by the well-recognized finding that patients with . . .