AJP - GI Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Gastrointest Liver Physiol 258: G308-G315, 1990;
0193-1857/90 $5.00
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Iwami, K.
Right arrow Articles by Johnson, L. R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Iwami, K.
Right arrow Articles by Johnson, L. R.

AJP - Gastrointestinal and Liver Physiology, Vol 258, Issue 2 308-G315, Copyright © 1990 by American Physiological Society

ARTICLES

Intestinal ornithine decarboxylase: half-life and regulation by putrescine

K. Iwami, J. Y. Wang, R. Jain, S. McCormack and L. R. Johnson
Department of Physiology and Cell Biology, University of Texas Medical School, Houston 77030.

Ornithine decarboxylase (ODC) is the primary rate-limiting enzyme for polyamine synthesis. ODC levels are increased in most tissues, including the intestinal mucosa, by growth-promoting agents. This enzyme has a brief half-life of from 5 to 30 min in mammalian tissues and is regulated by its product; putrescine. The current study examines the turnover and regulation of ODC in the mucosa of the small intestine. With the use of scraped intestinal mucosa from cycloheximide-treated rats, the time course of the decline in ODC activity yielded a half-life of approximately 22 min. Labeling enzyme protein with [3H]difluoromethylornithine (DFMO) resulted in a nearly identical estimation of half-life. ODC activity of mucosa from isolated gut segments stimulated by luminal glycine (0.1-0.4 M) was enhanced 60-100% by 10 mM putrescine administered luminally. Putrescine alone had no effect on ODC. In contrast, 10(-7) M putrescine prevented 80% of the ODC activity stimulated by asparagine in IEC-6 cells (a rat intestinal crypt cell line). The half-life of ODC in unstimulated IEC-6 cells was 20 min and increased to 35 min in cells exposed to 10 mM asparagine. These data demonstrate that ODC of nonproliferating villous cells is regulated differently from the identical enzyme in proliferating crypt cells. Therefore, conclusions regarding mucosal growth should not be based totally on ODC activity from whole mucosa, since it is essentially a measure of only the enzyme present in the villous cells.


This article has been cited by other articles:


Home page
 Am. J. Physiol. Endocrinol. Metab.Home page
D. L. Williamson, D. R. Bolster, S. R. Kimball, and L. S. Jefferson
Time course changes in signaling pathways and protein synthesis in C2C12 myotubes following AMPK activation by AICAR.
Am J Physiol Endocrinol Metab, July 1, 2006; 291(1): E80 - E89.
[Abstract] [Full Text] [PDF]

Home page
 J. Histochem. Cytochem.Home page
R. G. Schipper and A. A.J. Verhofstad
Distribution Patterns of Ornithine Decarboxylase in Cells and Tissues: Facts, Problems, and Postulates
J. Histochem. Cytochem., September 1, 2002; 50(9): 1143 - 1160.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Gastrointest. Liver Physiol.Home page
Q. Yuan, R. M. Ray, M. J. Viar, and L. R. Johnson
Polyamine regulation of ornithine decarboxylase and its antizyme in intestinal epithelial cells
Am J Physiol Gastrointest Liver Physiol, January 1, 2001; 280(1): G130 - G138.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online