These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Protection against liver injury by PGE1 or anti-TNF-alpha is associated with a reduction of TNF-R1 expression in hepatocytes.
    Author: Lozano JM, Collado JA, Medina T, Muntané J.
    Journal: Scand J Gastroenterol; 2003 Nov; 38(11):1169-75. PubMed ID: 14686721.
    Abstract:
    BACKGROUND: Tumour necrosis factor-alpha (TNF-5) has been shown to exacerbate or protect against liver injury in different experimental models. In a previous study, we observed that enhancement of TNF-alpha expression in hepatocytes by prostaglandin E1 (PGE1) pre-administration induced iNOS expression and cytoprotection against experimental liver injury in rats. Nevertheless, the reduction of TNF-alpha bioactivity by anti-TNF-alpha antibodies also reduced liver injury by D-GalN. The purpose of the present study was to evaluate whether protection by PGE1 or anti-TNF-alpha was related to a common effect on the membrane-bound TNF-alpha receptor expression. METHODS: Liver injury was induced in male Wistar rats by intraperitoneal injection of D-galactosamine (D-GalN) (1 g/kg). PGE1 or anti-TNF-alpha was administered at 30 or 60 min before D-GalN, respectively. Liver injury was evaluated by alanine aminotransferase (ALT) activity in serum and histological examination in liver sections. TNF-alpha was determined by ELISA in serum. The expression of TNF-alpha receptor type 1 (TNF-R1) and TNF-alpha receptor type 2 (TNF-R2) in hepatocytes was assessed by immunohistochemistry and immunoprecipitation + Western-blot analysis. RESULTS: PGE1 or anti-TNF-alpha reduced liver injury induced by D-GalN. Although PGE1 enhanced and anti-TNF-alpha reduced TNF-alpha concentration in serum, both protective treatments reduced the expression of TNF-R1 in hepatocytes. TNF-R2 was not detected in our experimental conditions. CONCLUSIONS: Our study showed that reduction of liver injury by PGE1 or anti-TNF-alpha antibodies was related to a reduction of TNF-R1 expression in hepatocytes.
    [Abstract] [Full Text] [Related] [New Search]