J Physiol Society Meetings
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
 QUICK SEARCH:   [advanced]


     


J Physiol Vol 252, Issue 3 pp 681-700
Copyright © 1975 by The Physiological Society
This Article
Right arrow Full Text (PDF)
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 Debnam, E S
Right arrow Articles by Levin, R J
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Debnam, E S
Right arrow Articles by Levin, R J

Effects of fasting and semistarvation on the kinetics of active and passive sugar absorption across the small intestine in vivo.

E S Debnam and R J Levin

The effects of dietary restriction on the kinetics of absorption in vivo of glucose, galactose and alpha-methyl glucoside were assessed by electrical and chemical methods in the rat jejunum. 2. The 'apparent Km', maximum absorption or Vmax (mu-mole/10 cm. 15 min) and maximum potential difference (p.d.max) were obtained for the jejunal electrogenic active transfer mechanism from the transfer p.d.s and the chemical absorption data corrected for diffusion using various graphical kinetic plots. 3. Fasting for 3 days greatly decreased the 'apparent Kms', obtained from electrical or chemical data, for all the sugars but had no effect on those for L-valine or L-methionine. Semistarvation caused a less pronounced reduction of the 'apparent Kms' for the sugars. The dietary-induced change in 'apparent Km' for glucose was also observed in the fasted hamster. One interpretation of these changes is that the affinity of the carriers for sugars increases during dietary restriction; the greater the level of restriction the greater the increase. 4. Fasting and semistarvation caused large reductions in the Vmax. These reductions were correlated with a reduced enterocyte population estimated by changes in enterocyte column size. 5. The reduction in the Vmax for galactose was mainly accounted for by the decrease in enterocyte population. In the case of glucose, other factors such as reduced enterocyte metabolism or changes in the carriers must be involved to explain the discrepancy between the large decrease in Vmax and the enterocyte column size. 6. Fasting and semi-starvation had complex, differential actions on the p.d.max for glucose, galactose and alpha-methyl glucoside. These changes did not correlate with those observed in the Vmax measured chemically. 7. A standard diet obtained from two commercial sources was found to differ greatly in its effect on the electrogenic transfer system for alpha-methyl glucoside but had no effect on those for galactose and glucose.




This article has been cited by other articles:


Home page
J. Physiol.Home page
C. Habold, C. Foltzer-Jourdainne, Y. Le Maho, J.-H. Lignot, and H. Oudart
Intestinal gluconeogenesis and glucose transport according to body fuel availability in rats
J. Physiol., July 15, 2005; 566(2): 575 - 586.
[Abstract] [Full Text] [PDF]


Home page
J ANIM SCIHome page
G. Gabel and J. R. Aschenbach
Influence of food deprivation on the transport of 3-O-methyl-{alpha}-D-glucose across the isolated ruminal epithelium of sheep
J Anim Sci, October 1, 2002; 80(10): 2740 - 2746.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
A. J. Hirsh and C. I. Cheeseman
Cholecystokinin Decreases Intestinal Hexose Absorption by a Parallel Reduction in SGLT1 Abundance in the Brush-Border Membrane
J. Biol. Chem., June 5, 1998; 273(23): 14545 - 14549.
[Abstract] [Full Text] [PDF]




HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1975 The Physiological Society.