Document Detail

Effect of physical activity and fasting on gut and liver proteolysis in the dog.
MedLine Citation:
PMID:  9435521     Owner:  NLM     Status:  MEDLINE    
The aim of this study was to determine how gut and liver protein kinetics adapt to acute exercise in the 18-h-fasted dog (n = 7) and in dogs glycogen depleted by a 42-h fast (n = 8). For this purpose, sampling (artery and portal and hepatic veins) and infusion (vena cava) catheters and Doppler flow probes (portal vein and hepatic artery) were implanted with animals under general anesthesia. At least 16 days later, an experiment, consisting of a 120-min equilibration period, a 30-min basal sampling period, and a 150-min exercise period, was performed. At the start of the equilibration period, a constant rate infusion of [1-13C]leucine was initiated. Gut and liver leucine appearance and disappearance rates were calculated in these studies by combining a novel stable isotopic method and arteriovenous difference methods. In the determination of tissue leucine kinetics the tissue inflow of both alpha-[13C]ketoisocaproic acid and [13C]leucine was taken into account. The results of this study show that 1) the splanchnic bed (liver plus gut) contributes approximately 40% to the whole body proteolytic rate in the basal state and during exercise in dogs fasted for either 18 or 42 h, 2) the contributions of the gut and liver to splanchnic bed proteolysis is about equal in the basal state in both 18- and 42-h-fasted dogs, and 3) exercise in the 18-h-fasted dog leads to a greater emphasis on gut proteolysis and a lesser emphasis on hepatic proteolysis. These studies highlight the important contribution of gut and hepatic proteolysis to whole body proteolysis and the ability of the gut to acutely adapt to changes in physical activity.
A E Halseth; P J Flakoll; E K Reed; A B Messina; M G Krishna; D B Lacy; P E Williams; D H Wasserman
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The American journal of physiology     Volume:  273     ISSN:  0002-9513     ISO Abbreviation:  Am. J. Physiol.     Publication Date:  1997 Dec 
Date Detail:
Created Date:  1998-02-09     Completed Date:  1998-02-09     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  0370511     Medline TA:  Am J Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  E1073-82     Citation Subset:  IM    
Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA.
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MeSH Terms
Carbon Isotopes
Digestive System / blood supply
Digestive System Physiological Phenomena*
Fasting / physiology*
Hepatic Artery / physiology
Hepatic Veins / physiology
Intestinal Absorption
Leucine / metabolism
Liver / blood supply,  physiology*
Models, Biological
Physical Exertion / physiology*
Portal Vein / physiology
Protein Biosynthesis
Proteins / metabolism*
Regional Blood Flow
Splanchnic Circulation / physiology
Time Factors
Grant Support
Reg. No./Substance:
0/Carbon Isotopes; 0/Proteins; 61-90-5/Leucine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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