Extracellular potassium homeostasis: Insights from hypokalemic periodic paralysis

Chih Jen Cheng, Elizabeth Kuo, Chou Long Huang

Research output: Contribution to journalArticle

39 Scopus citations

Abstract

Extracellular potassium makes up only about 2% of the total body's potassium store. The majority of the body potassium is distributed in the intracellular space, of which about 80% is in skeletal muscle. Movement of potassium in and out of skeletal muscle thus plays a pivotal role in extracellular potassium homeostasis. The exchange of potassium between the extracellular space and skeletal muscle is mediated by specific membrane transporters. These include potassium uptake by Na+, K+-adenosine triphosphatase and release by inward-rectifier K+ channels. These processes are regulated by circulating hormones, peptides, ions, and by physical activity of muscle as well as dietary potassium intake. Pharmaceutical agents, poisons, and disease conditions also affect the exchange and alter extracellular potassium concentration. Here, we review extracellular potassium homeostasis, focusing on factors and conditions that influence the balance of potassium movement in skeletal muscle. Recent findings that mutations of a skeletal muscle-specific inward-rectifier K+ channel cause hypokalemic periodic paralysis provide interesting insights into the role of skeletal muscle in extracellular potassium homeostasis. These recent findings are reviewed.

Original languageEnglish (US)
Pages (from-to)237-247
Number of pages11
JournalSeminars in Nephrology
Volume33
Issue number3
DOIs
Publication statusPublished - May 2013

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Keywords

  • Hypokalemia-induced paradoxical depolarization
  • Hypokalemic periodic paralysis
  • Inward-rectifier K channel
  • K-ATPase
  • Kir
  • Na
  • Skeletal muscle
  • Thyrotoxic periodic paralysis

ASJC Scopus subject areas

  • Nephrology

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