Thomas Damgaard Sandahl
Tumor necrosis factor-alpha acutely up-regulates urea synthesis in vivo in rats - a hepatic component of inflammatory catabolism?
Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review
- The Department of Hepatology and Gastroenterology V
- The Department of Endocrinology and Diabetes
Abstract Background. Catabolism is a serious problem in patients with active inflammation. The tissue nitrogen (N) depletion is related to increased hepatic capacity for elimination of N via conversion of amino-N into urea-N. This is caused by the inflammatory process, but the mediators responsible are unknown. Tumor necrosis factor-alpha (TNF-alpha) plays a key role in inflammation, and we hypothesized that TNF-alpha up-regulates urea synthesis. Methods. We examined the in vivo capacity of urea-N synthesis (CUNS) and mRNA levels of urea cycle enzyme genes 3 h after TNF-alpha injection in rats. Circulating concentrations of glucagon, corticosterone, insulin, glucose, cytokines and acute phase proteins and their liver tissue gene expressions were measured. Results. TNF-alpha increased CUNS by 40% (p=0.03) despite decreased urea-cycle enzyme gene expression. TNF-alpha increased interleukin 6 (IL-6) (p < 0.001); circulating acute phase proteins were unchanged. Conclusion. TNF-alpha in rats caused an acute up-regulation of the in vivo capacity of urea synthesis which may promote loss of nitrogen from the body and catabolism. The results indicate that TNF-alpha has a post-transcriptional effect on regulation of urea synthesis that is independent of the acute phase protein synthesis. Effects of IL-6 may be involved.
Original language | English |
---|
Book series | Scandinavian Journal of Clinical and Laboratory Investigation. Supplement |
---|
Volume | 70 |
---|
Issue | 3 |
---|
Pages (from-to) | 151-7 |
---|
Number of pages | 7 |
---|
ISSN | 0085-591X |
---|
DOIs | |
---|
Publication status | Published - 2010 |
---|
See relations at Aarhus University
Citationformats
ID: 19151969