Send to

Choose Destination
See comment in PubMed Commons below
J Cell Biochem. 2007 May 1;101(1):99-111.

Inhibitory effect of TNF-alpha on the intestinal absorption of galactose.

Author information

Department of Pharmacology and Physiology, Physiology Unit, Veterinary Faculty, University of Zaragoza, E-50013 Zaragoza, Spain.


Sepsis is a systemic response to infection in which toxins, such as bacterial lipopolysaccharide (LPS), stimulate the production of inflammatory mediators like the cytokine tumor necrosis factor alpha (TNF-alpha). Previous studies from our laboratory have revealed that LPS inhibits the intestinal absorption of L-leucine and D-fructose in rabbit when it was intravenously administered, and that TNF-alpha seems to mediate this effect on amino acid absorption. To extend this work, the present study was designed to evaluate the possible effect of TNF-alpha on D-galactose intestinal absorption, identify the intracellular mechanisms involved and establish whether this cytokine mediates possible LPS effects. Our findings indicate that TNF-alpha decreases D-galactose absorption both in rabbit intestinal tissue preparations and brush-border membrane vesicles. Western blot analysis revealed reduced amounts of the Na+/glucose cotransporter (SGLT1) protein in the plasma membrane attributable to the cytokine. On the contrary, TNF-alpha increased SGLT1 mRNA levels. Specific inhibitors of the secondary messengers PKC, PKA, the MAP kinases p38 MAP, JNK, MEK1/2 as well as the proteasome, diminished the TNF-alpha-evoked inhibitory effect. LPS inhibition of the uptake of the sugar was blocked by a TNF-alpha antagonist. In conclusion, TNF-alpha inhibits D-galactose intestinal absorption by decreasing the number of SGLT1 molecules at the enterocyte plasma membrane through a mechanism in which several protein-like kinases are involved.

[Indexed for MEDLINE]

Publication types, MeSH terms, Substances

Publication types

MeSH terms


PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Wiley
    Loading ...
    Support Center