Effects of intracellular magnesium on calcium, potassium and chloride channels.
Intracellular free magnesium activity approximates 0.6-0.8 mM. Variations in concentration around this physiologic range profoundly affect current flow through calcium, potassium and chloride channels. These effects are exerted on both inwardly and outwardly directed currents and appear to be independent of the state of phosphorylation of the channel. In the heart, these effects are manifested in changes in action potential duration, which may help to explain postulated links between hypomagnesemia and arrhythmias. In the kidney, effects of magnesium on ion channels may subserve a protective role and may explain how potassium balance is altered in magnesium depletion syndromes.
Kelepouris
E
E
Department of Physiology, University of Pennsylvania, Philadelphia 19104.
Kasama
R
R
Agus
Z S
ZS
D000818:Animals; D015220:Calcium Channels / Q000502:physiology*; D002712:Chlorides / Q000502:physiology*; D004594:Electrophysiology; D004848:Epithelium / Q000502:physiology; D006321:Heart / Q000502:physiology; D006801:Humans; D007668:Kidney / Q000502:physiology; D008274:Magnesium / Q000502:physiology*; D015221:Potassium Channels / Q000502:physiology*
D015220:Calcium Channels; D002712:Chlorides; D015221:Potassium Channels; D008274:Magnesium