Neurochemical Research

, Volume 22, Issue 6, pp 727–733

The γ-Glutamyl Transpeptidase Inhibitor Acivicin Preserves Glutathione Released by Astroglial Cells in Culture

Article

DOI: 10.1023/A:1027310328310

Cite this article as:
Dringen, R., Kranich, O. & Hamprecht, B. Neurochem Res (1997) 22: 727. doi:10.1023/A:1027310328310

Abstract

The release of glutathione from astroglial cells was investigated using astroglia-rich primary cultures prepared from the brains of newborn rats. These cells release glutathione after onset of an incubation in a glucose-containing minimal medium. The amount of extracellular glutathione increased with the time of incubation, although the accumulation slowed down gradually. An elevated rate of increase of the glutathione concentration in the incubation medium was found if the astroglial ectoenzyme γ-glutamyl transpeptidase was inhibited by acivicin. The activity of γ-glutamyl transpeptidase in astroglia-rich primary cultures, which was found to be 1.9 ± 0.3 nmol/(min × mg protein), was markedly reduced if the cells had been incubated in the presence of acivicin. After 2 h of incubation with acivicin half-maximal and maximal inhibition of γ-glutamyl transpeptidase activity was found at concentrations of about 5 μM and 50 μM, respectively. In the presence of acivicin at a concentration above 10 μM the glutathione content found released from astroglial cells apparently increased almost proportional to time for up to 10 h. Under these conditions the average rate of release was 2.1 ± 0.3 nmol/(h × mg protein) yielding after a 10 h incubation an extracellular glutathione content three times that of the medium of cells incubated without inhibitor. Half-maximal and maximal effects on the level of extracellular glutathione were found at 4 μM and 50 μM acivicin, respectively. After a 10 h incubation with acivicin the intracellular content of glutathione was reduced to 75% of the level of untreated astroglial cultures. These results suggest that glutathione released from astroglial cells can serve as substrate for the ectoenzyme γ-glutamyl transpeptidase of these cells.

Acivicinastrogliaectoenzymeγ-glutamyl transpeptidaseglutathioneprimary cultures

Copyright information

© Plenum Publishing Corporation 1997

Authors and Affiliations

  1. 1.Physiologisch-chemisches Institut der UniversitätTübingenGermany