title: Neomycin and bacitracin reduce the intestinal permeability in mice and increase the expression of some tight-junction proteins.
abstract: BACKGROUND
  Tight-junction (TJ) proteins regulate paracellular permeability. Gut permeability can be modulated by commensal microbiota. Manipulation of the gut microbiota with antibiotics like bacitracin and neomycin turned out to be useful for the treatment of diarrhoea induced by Clostridium difficile or chemotherapy drugs.
  
  
  OBJECTIVE
  To evaluate the effects of the microbiota depletion evoked by the oral administration of neomycin and bacitracin on the intestinal permeability and expression of TJ proteins in mice.
  
  
  METHODS
  Mice received neomycin and bacitracin orally for 7 days. Intestinal permeability was measured by the fluorescein-isothiocyanate-dextran (FITC-dextran) method. The gene expression of TJ proteins in the intestine was determined by real time-PCR.
  
  
  RESULTS
  FITC-dextran levels in serum were reduced by half in antibiotic-treated mice, indicating a reduction of intestinal permeability. Antibiotics increased the expression of zonula occludens 1 (ZO-1), junctional adhesion molecule A (JAM-A, and occludin in the ileum and ZO-1, claudin-3, and claudin-4 in the colon.
  
  
  CONCLUSIONS
  The combination of neomycin and bacitracin reduce intestinal permeability and increase the gene expression of ZO-1, junctional adhesion molecule A (JAM-A), and occludin in the ileum and ZO-1, claudin-3, and claudin-4 in the colon.
authors.affiliation: Farmacología y Fisiología, Universidad de Zaragoza, España.
authors.forename: Rebeca
authors.initials: R
authors.lastname: Nevado
authors.affiliation: Farmacología y Fisiología, Universidad de Zaragoza, España.
authors.forename: Raquel
authors.initials: R
authors.lastname: Forcén
authors.affiliation: Farmacología y Fisiología, Universidad de Zaragoza, España.
authors.forename: Elena
authors.initials: E
authors.lastname: Layunta
authors.affiliation: Farmacología y Fisiología, Universidad de Zaragoza. Facultad de Veterinaria, España.
authors.forename: María Divina
authors.initials: MD
authors.lastname: Murillo
authors.affiliation: Farmacología y Fisiologlía, Universidad de Zaragoza, España.
authors.forename: Laura
authors.initials: L
authors.lastname: Grasa
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001414:Bacitracin / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D007408:Intestinal Absorption / Q000187:drug effects*; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000187:drug effects; D051379:Mice; D009355:Neomycin / Q000494:pharmacology*; D010539:Permeability / Q000187:drug effects; D062725:Tight Junction Proteins / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D062725:Tight Junction Proteins; D001414:Bacitracin; D009355:Neomycin