Hepatic lactate uptake versus leg lactate output during exercise in humans

Copenhagen Muscle Research Center, Departments of 1 Anesthesiology and 2 Hepatology, Rigshospitalet, and 5 August Krogh Institute, University of Copenhagen, 4 Medical Department V, Aarhus University Hospital, Denmark, and 3 Cellular and Molecular Laboratory, Baker Heart Research Institute, Melbourne...

Full description

Saved in:
Bibliographic Details
Published in:Journal of applied physiology (1985) 2007-10, Vol.103 (4), p.1227-1233
Main Authors: Nielsen, H. B, Febbraio, M. A, Ott, P, Krustrup, P, Secher, N. H
Format: Article
Language:English
Subjects:
Adult
Biological and medical sciences
Blood
Blood Gas Analysis
Blood pressure
Exercise
Exercise - physiology
Exercise Test
Fundamental and applied biological sciences. Psychology
Glucose
Glucose - metabolism
Hemodynamics - physiology
Humans
Lactic Acid - metabolism
Leg - blood supply
Liver
Liver - blood supply
Liver - metabolism
Male
Muscle, Skeletal - metabolism
Oxygen Consumption - physiology
Regional Blood Flow - physiology
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Copenhagen Muscle Research Center, Departments of 1 Anesthesiology and 2 Hepatology, Rigshospitalet, and 5 August Krogh Institute, University of Copenhagen, 4 Medical Department V, Aarhus University Hospital, Denmark, and 3 Cellular and Molecular Laboratory, Baker Heart Research Institute, Melbourne, Australia Submitted 1 January 2007 ; accepted in final form 18 July 2007 The exponential rise in blood lactate with exercise intensity may be influenced by hepatic lactate uptake. We compared muscle-derived lactate to the hepatic elimination during 2 h prolonged cycling (62 ± 4% of maximal O 2 uptake, O 2max ) followed by incremental exercise in seven healthy men. Hepatic blood flow was assessed by indocyanine green dye elimination and leg blood flow by thermodilution. During prolonged exercise, the hepatic glucose output was lower than the leg glucose uptake (3.8 ± 0.5 vs. 6.5 ± 0.6 mmol/min; mean ± SE) and at an arterial lactate of 2.0 ± 0.2 mM, the leg lactate output of 3.0 ± 1.8 mmol/min was about fourfold higher than the hepatic lactate uptake (0.7 ± 0.3 mmol/min). During incremental exercise, the hepatic glucose output was about one-third of the leg glucose uptake (2.0 ± 0.4 vs. 6.2 ± 1.3 mmol/min) and the arterial lactate reached 6.0 ± 1.1 mM because the leg lactate output of 8.9 ± 2.7 mmol/min was markedly higher than the lactate taken up by the liver (1.1 ± 0.6 mmol/min). Compared with prolonged exercise, the hepatic lactate uptake increased during incremental exercise, but the relative hepatic lactate uptake decreased to about one-tenth of the lactate released by the legs. This drop in relative hepatic lactate extraction may contribute to the increase in arterial lactate during intense exercise. cycling; glucose; liver blood flow Address for reprint requests and other correspondence: H. Bay Nielsen, Dept. of Anesthesia 2041, Rigshospitalet, Blegdamsvej 9, 2100 København Ø, Denmark (e-mail: hbay{at}vip.cybercity.dk )
ISSN:8750-7587
1522-1601
DOI:10.1152/japplphysiol.00027.2007