Intestinal d-Galactose Transport in an Endotoxemia Model in the Rabbit

Abstract Lipopolysaccharide (LPS) is an endotoxin causing sepsis. Studies from our laboratory revealed impaired intestinal absorption of l-leucine and d-fructose in LPS-treated rabbits. The aim of this study was to examine intestinal d-galactose transport following intravenous administration of LPS...
Ausführliche Beschreibung

Abstract Lipopolysaccharide (LPS) is an endotoxin causing sepsis. Studies from our laboratory revealed impaired intestinal absorption of l-leucine and d-fructose in LPS-treated rabbits. The aim of this study was to examine intestinal d-galactose transport following intravenous administration of LPS in the rabbit and to identify the cellular mechanisms driving this process. Endotoxin treatment diminished the buildup of d-galactose in intestinal tissue, the mucosal to serosal transepithelial flux of the sugar and its uptake by brush border membrane vesicles (BBMVs). Intracellular signaling pathways associated with protein kinase C (PKC), protein kinase A (PKA), p38 mitogen-activated protein kinase (p38MAPK), Jun N-terminal kinase (JNK), MAPK/extracellular signal-regulated kinases 1 and 2 (MEK1/2) and proteasome were found to be involved in this reduction in sugar uptake. $ Na^{+} $/glucose cotransporter 1 (SGLT1) protein levels in BBMVs were lower for LPS-treated animals than control animals. These findings indicate that LPS inhibits the intestinal absorption of d-galactose via a complex cellular mechanism that could involve posttranscriptional regulation of the SGLT1 transporter. Ausführliche Beschreibung