title: [Effect of an acute exercise bout on Toll-like receptor 4 and inflammatory mechanisms in rat heart].
abstract: BACKGROUND
  Toll like receptor 4 (TLR-4) is a protein located in the cell membrane with an important function in the immune response of the organism. Its activation decreases heart contractility and activates nuclear transcription factor kappa B (NF-kB ). This in turn, increases the synthesis of different pro-inflammatory cytokines and the inducible enzyme nitric oxide (iNOS), which plays an important role in the inflammatory processes when nitric oxide production is enhanced.
  
  
  OBJECTIVE
  To determine if, after one session of acute exercise, expression of TLR-4 and iNOS, and activation of NF-kB are induced in rat cardiac tissue.
  
  
  METHODS
  Exercise and control groups of eight male Wistar rats each, were studied. The exercise group was subjected to an acute exercise bout lasting one hour. After the exercise, the heart was excised to measure the expression of iNOS and TLR-4 genes by quantitative polyme-rase chain reaction, NF-kB activation by electrophoretic mobility shift assay (EMSA) and p50 by Western blot.
  
  
  RESULTS
  After exercise, there was an increase in TLR-4 and of iNOS mRNA levels (+46.7 and +74.3% respectively). NF-kB activation and the nuclear expression of its p50 subunit also increased significantly (+240 and +306% respectively).
  
  
  CONCLUSIONS
  Increased expression of TLR4 following a session of acute exercise may contribute to the activation of the NF-kB signaling route, promoting the synthesis of nitric oxide, which could influence negatively the cardiac response to high intensity physical exercise.
authors.affiliation: Instituto de Biomedicina (IBIOMED), Universidad de León, Spain. uvmcristi@yahoo.es
authors.forename: Carlos
authors.initials: C
authors.lastname: Cristi-Montero
authors.forename: Pilar
authors.initials: P
authors.lastname: Sánchez-Collado
authors.forename: Christiano
authors.initials: C
authors.lastname: Veneroso
authors.forename: María José
authors.initials: MJ
authors.lastname: Cuevas
authors.forename: Javier
authors.initials: J
authors.lastname: González-Gallego
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D024202:Electrophoretic Mobility Shift Assay; D008297:Male; D009205:Myocarditis / Q000209:etiology*; D009206:Myocardium / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism*; D009569:Nitric Oxide / Q000096:biosynthesis*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051197:Toll-Like Receptor 4 / Q000378:metabolism*
chemical_list: D016328:NF-kappa B; C495347:Tlr4 protein, rat; D051197:Toll-Like Receptor 4; D009569:Nitric Oxide