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Disorders of Potassium: Physiology

  • Alluru S. ReddiEmail author
Chapter

Abstract

Potassium (K+) is the predominant intracellular cation in the body. The intracellular [K+] is 140–150 mEq/L; in blood it is 3.5–5 mEq/L. Serum contains a slightly higher concentration of K+ than plasma because K+ is released from red blood cells during clot formation. Maintenance of a high cellular concentration of K+ is necessary for several cellular functions, including growth, nucleic acid and protein synthesis, and regulation of cell volume, as well as pH and enzyme activation. In addition, a high intracellular concentration of K+ is essential to the maintenance of the resting membrane potential for cellular excitability and contraction. The high intracellular K+ concentration is maintained by the Na/K-ATPase located in the cell membranes of all animal cells. The activity of this enzyme is influenced by a variety of hormones. The kidney is the primary route for K+ excretion. In general, K+ excretion in the urine, called kaliuresis, parallels dietary intake. The other route for K+ excretion is the colon. Under conditions of decreased renal function, K+ excretion by the colon is enhanced.

Keywords

Kaliuresis Renal function and potassium Distal nephron Potassium excretion Potassium secretion 

Suggested Reading

  1. 1.
    Mount DB. Tubular potassium transport. In: Coffman TM, Falk RJ, Molitoris BA et al Editors. Schrier’s diseases of the kidney. Philadelphia: Lippincott Williams Wilkins; 2013, pp. 194–213.Google Scholar
  2. 2.
    Segal A. Potassium and the dyskalemias. In: Mount DB, Sayegh MH, Singh AJ, Editors. Core concepts in the disorders of fluid, electrolytes and acid-base balance. New York: Springer; 2013, pp. 49–102.Google Scholar

Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  1. 1.Department of Medicine Division of Nephrology and HypertensionRutgers New Jersey Medical SchoolNewarkUSA

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