Efectes de la suplementació dietètica amb proteïnes plasmàtiques sobre les propietats de barrera i de defensa de la mucosa intestinal en un model d'inflamació
SUMMARY: The aim of this study was to determine the potential modulatory effects of diets supplemented with spray-dried animal plasma (SDAP) or immunoglobulin concentrates (IC) on the of intestinal physiology of rats challenged with Staphylococcus aureus enterotoxin B (SEB). Lewis rats were fed diets containing 8% of SDAP, 4.7% of IC or milk proteins (Control diet) from postnatal day 21 (weaning) for 14 days. On days 30 and 33, rats were given SEB (50 ?g; i.p.). SEB induced an intestinal inflammation characterized by effects on intestinal immune system, on barrier function and on nutrient absorption. SEB administered rats showed an increase in T lymphocytes activation (in particular T helper lymphocytes) in Peyers Patches and in mesenteric lymph nodes, both responsible of immune response induction. Inflamed rats also showed an increase in water content in feces, neutrophil infiltration in intestinal mucosa, as well as an increase in local capillary permeability. SEB also alter barrier and nutrient absorption functions. The enterotoxin reduces the expression of proteins of the tight junction and of the adherent junction (ZO-1 and ?-catenina, respectively), as well as the transporter of D-glucosa. Feeding with SDAP or IC supplementation prevents the effect of the enterotoxin on the activation of T helper lymphocytes in Peyers patches. The dietary supplementation with SDAP (and in lower extent IC) reduces water content in feces and attenuates SEB effects on the epithelium, as well as on nutrients absorption and on the expression of proteins from tight and adherent junctions. In conclusion, the addition of plasma concentrates on feeding in the weaning period affects the distribution of some lymphocyte populations in the immune response to S. aureus, which prevents an overstimulation of intestinal immune system; at the same time, SDAP enhances the absorption of different energetic nutrients and the integrity of the epithelium. All in all supports the hypothesis that dietary supplementation with SDAP improves the nutrient intake and reduces the probability that chemic and infectious agents can enter to blood stream across the epithelial barrier. KEY WORDS: "Staphylococcus aureus", rat, intestinal inflammation, permeability, gut-associated immune tissue, SGLT-1, tight junction, spray-dried animal plasma, immunoglobulin concentrate, protein supplementation.
Advisor:Cambras Riu, Trinitat; Moretó Pedragosa, Miquel; Amat Miralles, Concepció
School:Universitat de Barcelona
Source Type:Master's Thesis
Keywords:fisiologia fac farmàcia
Date of Publication:02/05/2005