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Lower Xanthine Oxidoreductase Activity in Isolated Perfused Hearts if Xanthine Replaces Hypoxanthine as Substrate

  • M. Janssen
  • J. W. de Jong
  • A. S. Nieukoop
  • E. Keijzer
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 309A)

Abstract

In normal cardiac tissue xanthine oxidoreductase is present in the dehydrogenase form. During ischemia xanthine dehydrogenase is converted to xanthine oxidase, which generates free radicals during reperfusion. Both forms catalyze the breakdown of hypoxanthine to xanthine and xanthine to urate. Its activity can be measured with hypoxanthine or xanthine as substrate. Most widely xanthine is used as substrate because only one product is formed and therefore the enzyme activity can easily be determined. With hypoxanthine as substrate the difficult two-step reaction can raise problems if one wants to calculate the activity. Since either substrate is used in studies of xanthine oxidoreductase, this can explain the controversial data reported for various species.1,2,3

Keywords

Xanthine Oxidase Dehydrogenase Form Perfuse Heart Controversial Data Urate Concentration 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

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    J.W. de Jong, P. van der Meer, A.S. Nieukoop, T. Huizer, R.J. Stroeve, and E. Bos, Xanthine oxidoreductase activity in perfused hearts of various species, including humans, Circ. Res. 67:770 (1990).PubMedCrossRefGoogle Scholar
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Copyright information

© Springer Science+Business Media New York 1991

Authors and Affiliations

  • M. Janssen
    • 1
  • J. W. de Jong
    • 1
  • A. S. Nieukoop
    • 1
  • E. Keijzer
    • 1
  1. 1.Cardiochemical LaboratoryThoraxcenter Erasmus University RotterdamThe Netherlands

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