Membrane Ca2+ fluxes in rat hepatoma cells exposed to a supraphysiological concentration of asparagine

P. C.L. Wong*, K. P. Hau, David W F FONG

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)

Abstract

It has been shown that supraphysiological concentrations of asparagine and hypoosmotic shock stimulate ornithine decarboxylase activity in cultured cancer cells by increasing the synthesis and the half-life of the enzyme protein. Since extracellular Ca2+ is essential for the action of asparagine and is also important for cell volume regulation in certain cell types, aspects of Ca2+ physiology in asparagine-treated H-35 rat hepatoma cells were investigated. The initial rate of influx of 45Ca increased from 0.25 to 1.04 nmol/min/mg protein immediately after exposure to 10 mM asparagine. With a one-minute lag the efflux rate also increased 2.2-fold over a five minute period. Asparagine did not cause a net-gain in cellular Ca2+ as measured by 45Ca equilibration, nor did it have any effect on the cytosolic free Ca2+ as measured by Fura-2 fluorescence spectroscopy and Fluo-3 fluorescence confocal microscopy.

Original languageEnglish
Pages (from-to)1161-1167
Number of pages7
JournalBiochemistry and Molecular Biology International
Volume35
Issue number6
Publication statusPublished - 1995

Scopus Subject Areas

  • Biochemistry
  • Molecular Biology
  • Genetics

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