The Journal of Experimental Medicine
Torrey Pines Biolabs
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents

This Article
Right arrow Full Text (PDF, 911K)
Right arrow Alert me when this article is cited
Right arrow Citation Map
Services
Right arrow Email this article
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new content in the JEM
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by O'Donnell-Tormey, J.
Right arrow Articles by de la Harpe, J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by O'Donnell-Tormey, J.
Right arrow Articles by de la Harpe, J.
Social Bookmarking
 Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Facebook   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

Journal of Experimental Medicine, Vol 165, 500-514, Copyright © 1987 by Rockefeller University Press


ARTICLES

Secretion of pyruvate. An antioxidant defense of mammalian cells

J O'Donnell-Tormey, CF Nathan, K Lanks, CJ DeBoer and J de la Harpe

Cells in culture are exposed to marked oxidative stress, H2O2 being one of the predominant agents. Pyruvate and other alpha-ketoacids reacted rapidly, stoichiometrically, and nonenzymatically with H2O2, and they protected cells from its cytolytic effects. All five human and murine cell types studied, both malignant and nonmalignant, released pyruvate at an initial rate of 35-60 microM/h/2.5 X 10(6) cells when placed in 1 ml pyruvate-free medium. After 6-12 h a plateau of 60-150 microM pyruvate was attained, corresponding to concentrations reported for normal human serum and plasma. The rate of pyruvate accumulation was almost doubled in the presence of exogenous catalase, suggesting that released pyruvate functions as an antioxidant. The rate of pyruvate accumulation was dependent on cell number. Succinate, fumarate, citrate, oxaloacetate, alpha-ketoglutarate, and malate were not secreted in significant amounts from P815 cells; export was specific for pyruvate and lactate among the metabolites tested. Extracellular pyruvate was in equilibrium with intracellular stores. Thus, cells conditioned the extracellular medium with pyruvate at the expense of intracellular pyruvate, until homeostatic levels were attained in both compartments. We propose that cells plated at low density in the absence of exogenous pyruvate fail to thrive for two reasons: prolonged depletion of intracellular pyruvate and prolonged vulnerability to oxidant stress.
Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Facebook Facebook   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?


This article has been cited by other articles:



  Home | Help | Feedback | Subscriptions | Archive | Search
TABLE OF CONTENTS