Effect of dibutyryl cyclic AMP on the kinetics of myo-inositol transport in cultured astrocytes

Russell E. Isaacks, Alexander S. Bender, Jayne S. Reuben, Chang Y. Kim, You F. Shi, Michael D. Norenberg

Research output: Contribution to journalArticle

6 Scopus citations

Abstract

Dibutyryl cyclic AMP (dBcAMP) is known to induce maturation and differentiation in astrocytes. As myo-inositol is an important osmoregulator in astrocytes, we examined the effects of maturation and biochemical differentiation on the kinetic properties of myo-inositol transport. Treatment of astrocytes with dBcAMP significantly decreased the V(max) of myo-inositol uptake, but the effect on K(m) was not significant. The myo- inositol content of astrocytes was significantly decreased in cells treated for 5 days with dBcAMP as compared with untreated controls. Maximum suppression of myo-inositol uptake occurred 7 days after exposure of astrocytes to dBcAMP; this was gradually reversible when dBcAMP was removed from the medium. After exposure to hypertonic medium for 6 h, mRNA expression of the myo-inositol co-transporter was diminished by ~36% in astrocytes treated with dBcAMP as compared with untreated cells. It appears that myo- inositol transporters in astrocytes treated with dBcAMP are either decreased in number or inactivated during maturation and differentiation, suggesting that the stage of differentiation and biochemical maturation of astrocytes is an important factor in osmoregulation.

Original languageEnglish (US)
Pages (from-to)105-111
Number of pages7
JournalJournal of neurochemistry
Volume73
Issue number1
DOIs
StatePublished - Jul 1 1999

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Keywords

  • Astrocytes
  • Dibutyryl cyclic AMP
  • Myo-Inositol content
  • Myo-Inositol transport
  • Myo-Inositol transporter mRNA
  • Osmoregulation

ASJC Scopus subject areas

  • Biochemistry
  • Cellular and Molecular Neuroscience

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