Translations:Potassium/60/en

Renal filtration, reabsorption, and excretion

Renal handling of potassium is closely connected to sodium handling. Potassium is the major cation (positive ion) inside animal cells (150 mmol/L, 4.8 g/L), while sodium is the major cation of extracellular fluid (150 mmol/L, 3.345 g/L). In the kidneys, about 180 liters of plasma is filtered through the glomeruli and into the renal tubules per day. This filtering involves about 600 mg of sodium and 33 mg of potassium. Since only 1–10 mg of sodium and 1–4 mg of potassium are likely to be replaced by diet, renal filtering must efficiently reabsorb the remainder from the plasma.