|
|
||||||||
is involved
1Department of Medical Biosciences, Physiological Chemistry, University of Umeå, SE-90187, Umeå, Sweden; and 2Department of Molecular Biomedical Research, VIB/Ghent University, B-9052 Ghent, Belgium
Submitted 10 June 2003 ; accepted in final form 12 December 2003
When food was removed from young rats in the early morning, adipose tissue tumor necrosis factor (TNF)-
activity increased 50% and lipoprotein lipase (LPL) activity decreased 70% in 6 h. There was a strong negative correlation between the TNF-
and LPL activities. Exogenous TNF-
further decreased LPL activity. Pentoxifylline, known to decrease production of TNF-
, had no effect on LPL activity in fed rats but almost abolished the rise of TNF-
and the decrease of LPL activity in rats deprived of food. The specific activity of LPL decreased from 0.92 mU/ng in fed rats to 0.35 and 0.24 mU/ng in rats deprived of food given saline or TNF-
, indicating a shift in the LPL molecules toward an inactive state. Lipopolysaccharide increased adipose tissue TNF-
and decreased LPL activity. Both of these effects were strongly impeded by pretreatment of the rats with pentoxifylline, or dexamethasone. Pretreatment of the rats with actinomycin D virtually abolished the response of LPL activity to food deprivation or exogenous TNF-
. We conclude that food deprivation, like lipopolysaccharide, signals via TNF-
to a gene whose product causes a rapid shift of newly synthesized LPL molecules toward an inactive form and thereby shuts down extraction of lipoprotein triglycerides by the adipose tissue.
adipocytes; cytokines; endothelium; fasting; heparin; lipopolysaccharide; rat; secretion; tumor necrosis factor-
This article has been cited by other articles:
![]() |
J. J. Loor, H. M. Dann, N. A. J. Guretzky, R. E. Everts, R. Oliveira, C. A. Green, N. B. Litherland, S. L. Rodriguez-Zas, H. A. Lewin, and J. K. Drackley Plane of nutrition prepartum alters hepatic gene expression and function in dairy cows as assessed by longitudinal transcript and metabolic profiling Physiol Genomics, January 12, 2007; 27(1): 29 - 41. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. Sukonina, A. Lookene, T. Olivecrona, and G. Olivecrona Angiopoietin-like protein 4 converts lipoprotein lipase to inactive monomers and modulates lipase activity in adipose tissue PNAS, November 14, 2006; 103(46): 17450 - 17455. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. C TSIOTRA and C. TSIGOS Stress, the Endoplasmic Reticulum, and Insulin Resistance Ann. N.Y. Acad. Sci., November 1, 2006; 1083(1): 63 - 76. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. L. Magnusson-Olsson, B. Hamark, A. Ericsson, M. Wennergren, T. Jansson, and T. L. Powell Gestational and hormonal regulation of human placental lipoprotein lipase J. Lipid Res., November 1, 2006; 47(11): 2551 - 2561. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. W. Zderic and M. T. Hamilton Physical inactivity amplifies the sensitivity of skeletal muscle to the lipid-induced downregulation of lipoprotein lipase activity J Appl Physiol, January 1, 2006; 100(1): 249 - 257. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |