[Physiological role of Mg2+ in neurons].
Physiological role of Mg ions in living cells is now in the process of reexamination. This is triggered by the finding that cytoplasmic Mg(2+) concentration measured by a fluorescent dye, mag fura-2, is surprisingly small, being not more than 1 mM. Lines of examination have revealed that Mg(2+) inhibits various species of ionc channels not only from outside but also from inside of the plasma membrane. Entry of Mg(2+) into intracellular space is revealed to take place via a Ca(2+)-channels, TRPM7; this channel may thus be called "Mg(2+)-channel". Moreover, an excess amount of intracellular Mg(2+) induced by hyper-activity of NMDA channels occasionally causes neuronal cell death as a result of inhibitory effects of Mg(2+) to mitochondrial activities.
Sato
Yoshiaki
Y
Department of Physiology, National Defense Medical College.
Fukuda
Jun
J
D002118:Calcium / Q000502:physiology; D002413:Cations, Divalent; D016923:Cell Death; D018698:Glutamic Acid / Q000633:toxicity; D006706:Homeostasis; D007473:Ion Channels / Q000502:physiology; D008274:Magnesium / Q000502:physiology*; D008565:Membrane Proteins / Q000502:physiology; D008928:Mitochondria / Q000502:physiology; D009474:Neurons; D011494:Protein Kinases / Q000502:physiology; D017346:Protein Serine-Threonine Kinases; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000502:physiology; D050053:TRPM Cation Channels
D002413:Cations, Divalent; D007473:Ion Channels; D008565:Membrane Proteins; D016194:Receptors, N-Methyl-D-Aspartate; D050053:TRPM Cation Channels; D018698:Glutamic Acid; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; C486583:TRPM7 protein, human; D008274:Magnesium; D002118:Calcium