J García-Herrera1, B Abad, M J Rodríguez-Yoldi. 1. Physiology Unit, Dept. of Pharmacology and Physiology, Veterinary Faculty, University of Zaragoza, Miguel Servet 177, 50013 Zaragoza, Spain.
Abstract
OBJECTIVE: To investigate alterations in the transport of D-fructose across the rabbit jejunum when the gut is exposed in vitro to lipopolysaccharide (LPS), an endotoxin causative agent of sepsis. MATERIALS AND METHODS: D-fructose intestinal transport was assesed employing three techniques: sugar uptake measurements in rings of everted jejunum (micromol/D-fructose/ml cell water), transepithelial flux measurements in Ussing-type chambers (micromol D-fructose/cm2/h) and transport assays in preparation of brush border membrane vesicles (pmoles D-fructose/mg protein). Samples were taken from the bathing solution and from the extracts of the tissue for radioactivity counting. RESULTS: Adding LPS (3 microg/ml) to tissue decreased the uptake and mucosal to serosal flux of 5 mM D-fructose across the enterocyte. LPS did not modify sugar uptake across brush border membrane vesicles. The inhibitory effect of LPS was suppressed by W-13 (5 x 10(-6) M), a Ca-calmodulin antagonist, and staurosporine (10(-7) and 10(-6) M) and GF-109203X (10(-6) M) a nonselective and selective protein kinase C (PKC) inhibitor respectively. Tumor Necrosis Factor (TNF-alpha), an immunoregulatory cytokine involved in septic responses occurring during bacterial infection at concentrations 3 x 10(-4) to 3 microg/ml, did not affect the sugar transport. CONCLUSIONS: LPS can inhibit the intestinal uptake of D-fructose across the rabbit jejunum in vitro by intracellular processes related to PKC and calmodulin protein.
OBJECTIVE: To investigate alterations in the transport of D-fructose across the rabbit jejunum when the gut is exposed in vitro to lipopolysaccharide (LPS), an endotoxin causative agent of sepsis. MATERIALS AND METHODS:D-fructose intestinal transport was assesed employing three techniques: sugar uptake measurements in rings of everted jejunum (micromol/D-fructose/ml cell water), transepithelial flux measurements in Ussing-type chambers (micromol D-fructose/cm2/h) and transport assays in preparation of brush border membrane vesicles (pmoles D-fructose/mg protein). Samples were taken from the bathing solution and from the extracts of the tissue for radioactivity counting. RESULTS: Adding LPS (3 microg/ml) to tissue decreased the uptake and mucosal to serosal flux of 5 mM D-fructose across the enterocyte. LPS did not modify sugar uptake across brush border membrane vesicles. The inhibitory effect of LPS was suppressed by W-13 (5 x 10(-6) M), a Ca-calmodulin antagonist, and staurosporine (10(-7) and 10(-6) M) and GF-109203X (10(-6) M) a nonselective and selective protein kinase C (PKC) inhibitor respectively. Tumor Necrosis Factor (TNF-alpha), an immunoregulatory cytokine involved in septic responses occurring during bacterial infection at concentrations 3 x 10(-4) to 3 microg/ml, did not affect the sugar transport. CONCLUSIONS:LPS can inhibit the intestinal uptake of D-fructose across the rabbit jejunum in vitro by intracellular processes related to PKC and calmodulin protein.
Authors: Veedamali S Subramanian; Subrata Sabui; Hamid Moradi; Jonathan S Marchant; Hamid M Said Journal: Biochim Biophys Acta Biomembr Date: 2017-10-10 Impact factor: 3.747
Authors: P Amador; J García-Herrera; M C Marca; J de la Osada; S Acín; M A Navarro; M T Salvador; M P Lostao; M J Rodríguez-Yoldi Journal: J Membr Biol Date: 2007-06-12 Impact factor: 1.843