Na+/Mg2+ transporter acts as a Mg2+ buffering mechanism in PC12 cells

Takeshi Kubota, Kentaro Tokuno, Jun Nakagawa, Yoshiichiro Kitamura, Hiroto Ogawa, Yoshio Suzuki, Koji Suzuki, Kotaro Oka

Research output: Contribution to journalArticle

24 Citations (Scopus)

Abstract

Mg2+ buffering mechanisms in PC12 cells were demonstrated with particular focus on the role of the Na+/Mg2+ transporter by using a newly developed Mg2+ indicator, KMG-20, and also a Na+ indicator, Sodium Green. Carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone (FCCP), a protonophore, induced a transient increase in the intracellular Mg2+ concentration ([Mg2+]i). The rate of decrease of [Mg2+]i was slower in a Na+-free extracellular medium, suggesting the coupling of Na+ influx and Mg2+ efflux. Na+ influxes were different for normal and imipramine- (a putative inhibitor of the Na+/Mg2+ transporter) containing solutions. FCCP induced a rapid increase in [Na+]i in the normal solution, while the increase was gradual in the imipramine-containing solution. The rate of decrease of [Mg2+]i in the imipramine-containing solution was also slower than that in the normal solution. From these results, we show that the main buffering mechanism for excess Mg2+ depends on the Na+/Mg2+ transporter in PC12 cells.

Original languageEnglish
Pages (from-to)332-336
Number of pages5
JournalBiochemical and Biophysical Research Communications
Volume303
Issue number1
DOIs
Publication statusPublished - 2003 Mar 28

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Keywords

  • FCCP
  • Imipramine
  • KMG-20
  • Sodium Green

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology

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