| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Department of Nutritional Sciences, University of California, Berkeley, California 94720-3104
The objectives of this study were to establish a reliable method for quantifying glycolytic flux in intestinal epithelial cells, to determine the proportion of energy provided to small intestine epithelial cells by glucose vs. glutamine, and to determine whether there was an energetic advantage to having both substrates present simultaneously. There was substantial retention of 3H in alanine and lactate when [2-3H]glucose was used as tracer for quantifying glycolysis, and the magnitude of the 3H retention was influenced by the presence of other substrates and metabolites. Detritiation was at least 99% complete, however, when [3-3H]glucose was used as tracer in this system and the tritium was recovered as 3H2O. Glycolytic flux was six- to sevenfold higher in cells of the proximal than distal small intestine but was not significantly different for young adult (4 mo) vs. aged adult (24 mo) rats. Net ATP production from exogenous substrates was higher when both glucose and glutamine were present simultaneously than when either substrate was present alone, and glucose was calculated to provide 50-60% of the net ATP produced from these two substrates. Most of the energy produced from glucose was produced via the anaerobic metabolic pathways (78% for glucose alone, 95% with glucose and glutamine). Net energy production was calculated to be 10% lower in cells from aged animals than in those from young animals, since CO2 production from these major substrates was lower in cells from aged animals.
detritiation; method
This article has been cited by other articles:
|
|
 |
|
  K. A. Kles and K. A. Tappenden Hypoxia differentially regulates nutrient transport in rat jejunum regardless of luminal nutrient present Am J Physiol Gastrointest Liver Physiol, December 1, 2002; 283(6): G1336 - G1342. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. P. Lambert, L. J. Broussard, B. L. Mason, W. J. Mauermann, and C. V. Gisolfi Gastrointestinal permeability during exercise: effects of aspirin and energy-containing beverages J Appl Physiol, June 1, 2001; 90(6): 2075 - 2080. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Abely, P. Dallet, M. Boisset, and J. F. Desjeux Effect of cholera toxin on glutamine metabolism and transport in rabbit ileum Am J Physiol Gastrointest Liver Physiol, May 1, 2000; 278(5): G789 - G796. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. J. Reeds, D. G. Burrin, B. Stoll, and F. Jahoor Intestinal Glutamate Metabolism J. Nutr., April 1, 2000; 130(4): 978 - 978. [Abstract] [Full Text]
|
|
|
|
 |
|
 B. Stoll, D. G. Burrin, J. Henry, H. Yu, F. Jahoor, and P. J. Reeds Substrate oxidation by the portal drained viscera of fed piglets Am J Physiol Endocrinol Metab, July 1, 1999; 277(1): E168 - E175. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Quan, M. D. Fitch, and S. E. Fleming Rate at which glutamine enters TCA cycle influences carbon atom fate in intestinal epithelial cells Am J Physiol Gastrointest Liver Physiol, December 1, 1998; 275(6): G1299 - G1308. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. W. Lopez, C. Moundras, C. Morand, C. Demigné, and C. Rémésy Opposite Fluxes of Glutamine and Alanine in the Splanchnic Area Are an Efficient Mechanism for Nitrogen Sparing in Rats J. Nutr., September 1, 1998; 128(9): 1487 - 1494. [Abstract] [Full Text]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
