title: Acute exercise induce endothelial nitric oxide synthase phosphorylation via Akt and AMP-activated protein kinase in aorta of rats: Role of reactive oxygen species.
abstract: BACKGROUND
  Acute exercise increases reactive oxygen species (ROS) levels, including hydrogen peroxide (H2O2). H2O2 promotes endothelial nitric oxide synthase (eNOS) activation and phosphorylation in endothelial cells. With this in mind, the present study was designed to evaluate ex vivo eNOS phosphorylation in rat aortas incubated with H2O2 and to test this hypothesis in vivo in the aortas of rats submitted to acute exercise.
  
  
  METHODS
  For ex vivo studies, six groups of aortic tissue were formed: control, H2O2, N-acetylcysteine (NAC), LY294002, compound C, and LY294002 plus compound C. While incubation with H2O2 increased Akt, AMPK and eNOS phosphorylation, pre-incubation with NAC strongly reduced the phosphorylation of these enzymes. For in vivo studies, male Wistar rats were divided into four groups: control, cont+NAC, exercise, and exer+NAC. After a 3h swimming session, animals were decapitated and aortas were excised for biochemical and immunoblotting analysis.
  
  
  RESULTS
  Acute exercise increased superoxide levels and dichlorofluorescein (DCF) concentrations, and this increase was related to phosphorylation of Akt, AMPK and eNOS. On the other hand, use of NAC reduced superoxide levels and DCF concentration. Reduced superoxide levels and DCF in the exer+NAC group were associated with decreased Akt, AMPK and eNOS phosphorylation. These results appear to be connected with vascular function because VASP phosphorylation increased in acute exercise and decreased in exer+NAC.
  
  
  CONCLUSIONS
  Our results indicate that ROS induced by acute exercise play the important role of activating eNOS, a process apparently mediated by Akt and AMPK.
authors.affiliation: Laboratory of Exercise Biochemistry and Physiology, Postgraduate Program in Health Sciences, Universidade do Extremo Sul Catarinense, Criciúma, SC, Brazil.
authors.forename: Viviane A
authors.initials: VA
authors.lastname: Barbosa
authors.forename: Thais F
authors.initials: TF
authors.lastname: Luciano
authors.forename: Scherolin O
authors.initials: SO
authors.lastname: Marques
authors.forename: Marcelo F
authors.initials: MF
authors.lastname: Vitto
authors.forename: Daniela R
authors.initials: DR
authors.lastname: Souza
authors.forename: Luciano A
authors.initials: LA
authors.lastname: Silva
authors.forename: João Paulo A
authors.initials: JP
authors.lastname: Santos
authors.forename: José C
authors.initials: JC
authors.lastname: Moreira
authors.forename: Felipe
authors.initials: F
authors.lastname: Dal-Pizzol
authors.forename: Fabio S
authors.initials: FS
authors.lastname: Lira
authors.forename: Ricardo A
authors.initials: RA
authors.lastname: Pinho
authors.forename: Claudio T
authors.initials: CT
authors.lastname: De Souza
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000378:metabolism*; D000818:Animals; D001013:Aorta, Thoracic / Q000201:enzymology*; D008297:Male; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D010766:Phosphorylation / Q000502:physiology; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013997:Time Factors
chemical_list: D017382:Reactive Oxygen Species; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat; D051057:Proto-Oncogene Proteins c-akt; D055372:AMP-Activated Protein Kinases