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.

Transforming Growth Factor α May Be a Physiological Regulator of Liver Regeneration by means of an Autocrine Mechanism

Janet E. Mead and Nelson Fausto
Proceedings of the National Academy of Sciences of the United States of America
Vol. 86, No. 5 (Mar. 1, 1989), pp. 1558-1562
Stable URL: http://www.jstor.org/stable/33236
Page Count: 5
  • 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.
Transforming Growth Factor α  May Be a Physiological Regulator of Liver Regeneration by means of an Autocrine Mechanism
Preview not available

Abstract

We investigated whether transforming growth factor α (TGF-α ) is involved in hepatocyte growth responses both in vivo and in culture. During liver regeneration after partial hepatectomy in rats, TGF-α mRNA increased; it reached a maximum (≈ 9-fold higher than normal) at the peack of DNA synthesis. The message and the peptide were localized in hepatocytes and found in higher amounts in hepatocytes obtained from regenerating liver. TGF-α caused a 13-fold elevation of DNA synthesis in hepatocytes in primary culture and was slightly more effective than epidermal growth factor. TGF-β blocked TGF-α stimulation when added either simultaneously with TGF-α or a day later. TGF-α message increased in hepatocytes stimulated to undergo DNA synthesis by TGF-α or epidermal growth factor, and the peptide was detected in the culture medium by RIA. In the regenerating liver, the increase in TGF-α mRNA during the first day after partial hepatectomy coincided with an increase in epidermal growth factor/TGF-α receptor mRNA and a decrease (already reported) in the number of these receptors. We conclude that TGF-α may function as a physiological inducer of hepatocyte DNA synthesis during liver regeneration by means of an autocrine mechanism and that its stimulatory effects in this growth process are balanced by the inhibitory action of TGF-β 1.

Page Thumbnails

  • Thumbnail: Page 
1558
    1558
  • Thumbnail: Page 
1559
    1559
  • Thumbnail: Page 
1560
    1560
  • Thumbnail: Page 
1561
    1561
  • Thumbnail: Page 
1562
    1562