|
|
||||||||
1Section of Leukocyte Biology,2Critical Care Section,3.S. Department of Agriculture, Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030
Submitted 25 March 2003 ; accepted in final form 5 June 2003
Hindlimb unloading (HU) is known to induce physiological alterations in various organ systems that mimic some responses observed after exposure to microgravity. In the present study, the effects of up to 4 wk of HU on the liver were assessed in male Wistar rats and two mouse strains: endotoxin-sensitive C57BL/6 mice and endotoxin-resistant C3H/HEJ mice. Plasma levels of endotoxin, a known stimulator of hepatic injury, were measured in portal and systemic blood samples. Endotoxin was elevated by
50% in portal blood samples of mice and rats but was not detectable in systemic blood. This low-grade portal endotoxemia was associated with hepatic injury in rats and C57BL/6 mice as indicated by inflammation and elevated serum transaminase activities. Blood levels of the cytokine TNF-
were increased by
50% in C57BL/6 mice; no significant elevation of this cytokine was detected in rats. Messenger RNA levels of the acute-phase proteins serum amyloid A, haptoglobin, and lipopolysaccharide binding protein were significantly enhanced after 3 wk of HU in endotoxin-sensitive rodents. In contrast, no histological changes or significant increases in serum enzyme activity were detected after HU in C3H/HEJ mice despite portal endotoxin levels of 222 ± 83.4 pg/ml. At the 3-wk time point, expression of acute-phase proteins was not elevated in C3H/HEJ mice; however, expression after 4 wk of HU was similar to endotoxin-sensitive rodents. In conclusion, these findings indicate that HU induced mild portal endotoxemia, which contributed to the observed hepatic injury in endotoxin-sensitive rodents.
endotoxin; liver; hindlimb suspension
This article has been cited by other articles:
![]() |
P. D. Cani, R. Bibiloni, C. Knauf, A. Waget, A. M. Neyrinck, N. M. Delzenne, and R. Burcelin Changes in Gut Microbiota Control Metabolic Endotoxemia-Induced Inflammation in High-Fat Diet-Induced Obesity and Diabetes in Mice Diabetes, June 1, 2008; 57(6): 1470 - 1481. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. A. Rivera, S. H. Abrams, M. H. Tcharmtchi, M. Allman, T. T. Ziba, M. J. Finegold, and C. W. Smith Feeding a corn oil/sucrose-enriched diet enhances steatohepatitis in sedentary rats Am J Physiol Gastrointest Liver Physiol, February 1, 2006; 290(2): G386 - G393. [Abstract] [Full Text] [PDF] |
||||
![]() |
Z. Li, C. A. Rivera, A. R. Burns, and C. W. Smith Hindlimb unloading depresses corneal epithelial wound healing in mice J Appl Physiol, August 1, 2004; 97(2): 641 - 647. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |