Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Biliverdin Reductase: A Major Physiologic Cytoprotectant

David E. Barañano, Mahil Rao, Christopher D. Ferris and Solomon H. Snyder
Proceedings of the National Academy of Sciences of the United States of America
Vol. 99, No. 25 (Dec. 10, 2002), pp. 16093-16098
Stable URL: http://www.jstor.org/stable/3073913
Page Count: 6
  • Read Online (Free)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Biliverdin Reductase: A Major Physiologic Cytoprotectant
Preview not available

Abstract

Bilirubin, an abundant pigment that causes jaundice, has long lacked any clear physiologic role. It arises from enzymatic reduction by biliverdin reductase of biliverdin, a product of heme oxygenase activity. Bilirubin is a potent antioxidant that we show can protect cells from a 10,000-fold excess of H2O 2. We report that bilirubin is a major physiologic antioxidant cytoprotectant. Thus, cellular depletion of bilirubin by RNA interference markedly augments tissue levels of reactive oxygen species and causes apoptotic cell death. Depletion of glutathione, generally regarded as a physiologic antioxidant cytoprotectant, elicits lesser increases in reactive oxygen species and cell death. The potent physiologic antioxidant actions of bilirubin reflect an amplification cycle whereby bilirubin, acting as an antioxidant, is itself oxidized to biliverdin and then recycled by biliverdin reductase back to bilirubin. This redox cycle may constitute the principal physiologic function of bilirubin.

Page Thumbnails

  • Thumbnail: Page 
[16093]
    [16093]
  • Thumbnail: Page 
16094
    16094
  • Thumbnail: Page 
16095
    16095
  • Thumbnail: Page 
16096
    16096
  • Thumbnail: Page 
16097
    16097
  • Thumbnail: Page 
16098
    16098