Diabetologia

, Volume 37, Issue 3, pp 264–269

Abnormal glutathione metabolism and increased cytotoxicity caused by H2O2 in human umbilical vein endothelial cells cultured in high glucose medium

  • A. Kashiwagi
  • T. Asahina
  • M. Ikebuchi
  • Y. Tanaka
  • Y. Takagi
  • Y. Nishio
  • R. Kikkawa
  • Y. Shigeta
Originals

DOI: 10.1007/BF00398053

Cite this article as:
Kashiwagi, A., Asahina, T., Ikebuchi, M. et al. Diabetologia (1994) 37: 264. doi:10.1007/BF00398053

Summary

To determine whether increased oxidative stress in diabetes mellitus is due to an impaired freeradical scavenger function in endothelial cells, GSH-dependent H2O2 degradation in human umbilical vein endothelial cells was studied. The GSH-dependent, NaN3-uninhibitable H2O2-degradation in endothelial cells was reduced by 48% (p <0.001) when the cells were exposed to 33 mmol/l d-glucose vs 5.5 mmol/l d-glucose. This impairment was dependent not only on the d-glucose concentration in the medium but also on d-glucose specific metabolism, since neither 27.5 mmol/l l-glucose nor 27.5 mmol/l d-raffinose had any effect on the peroxide degradation activity. Activation of the glutathione redox cycle by H2O2 in cells exposed to high glucose concentrations was attenuated as compared with 5.5 mmol/l d-glucose because of: 1) a 42% decrease (p <0.001) in intracellular NADPH content, and 2) a 34% reduction (p <0.01) in glutathione release into the media. This results in an accumulation of GSSG in the cells following exposure to H2O2. Both H2O2-evoked 51Cr-release and H2O2-induced endothelial cell damage were significantly (p <0.01) greater in the 33 mmol/l d-glucose group than in the 5.5 mmol/l d-glucose group. These results indicate that the abnormal glutathione redox cycle observed in endothelial cells is induced by high glucose concentrations in the medium, resulting in an impairment of reduced GSH-dependent H2O2-degradation. These abnormalities may associate with the increased cellular damage following an exogenous exposure to H2O2.

Key words

Human umbilical vein endothelial cellshigh glucoseoxygen radicalsradical scavengerglutathione redox cycle

Abbreviations

GSH

Reduced glutathione

GSSG

oxidized glutathione

BSO

L-buthionine-[S,R]-sulfoximine

Copyright information

© Springer-Verlag 1994

Authors and Affiliations

  • A. Kashiwagi
    • 1
  • T. Asahina
    • 1
  • M. Ikebuchi
    • 1
  • Y. Tanaka
    • 1
  • Y. Takagi
    • 1
  • Y. Nishio
    • 1
  • R. Kikkawa
    • 1
  • Y. Shigeta
    • 1
  1. 1.Third Department of MedicineShiga University of Medical ScienceShigaJapan