1. Role of magnesium in ROMK potassium channel function.
Role of magnesium in ROMK potassium channel function. Potassium is the most abundant intracellular cation, creating a large chemical gradient that favors the outward flow of K+ through ROMK. (Left panel) Normally, magnesium binds to a cytosol-exposed site in ROMK to limit this outward flow. (Right panel) During hypomagnesemia, fewer Mg2+ ions can bind to this site, and K+ is secreted more freely. Thus, magnesium deficiency causes K+ wasting. This likely explains why magnesium repletion is required to efficiently restore potassium concentrations to normal during concomitant hypomagnesemia and hypokalemia.
Arohan R. Subramanya, and David H. Ellison CJASN 2014;9:
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