title: Swimming training induces liver mitochondrial adaptations to oxidative stress in rats submitted to repeated exhaustive swimming bouts.
abstract: OBJECTIVE
  Although acute exhaustive exercise is known to increase liver reactive oxygen species (ROS) production and aerobic training has shown to improve the antioxidant status in the liver, little is known about mitochondria adaptations to aerobic training. The main objective of this study was to investigate the effects of the aerobic training on oxidative stress markers and antioxidant defense in liver mitochondria both after training and in response to three repeated exhaustive swimming bouts.
  
  
  METHODS
  Wistar rats were divided into training (n = 14) and control (n = 14) groups. Training group performed a 6-week swimming training protocol. Subsets of training (n = 7) and control (n = 7) rats performed 3 repeated exhaustive swimming bouts with 72 h rest in between. Oxidative stress biomarkers, antioxidant activity, and mitochondria functionality were assessed.
  
  
  RESULTS
  Trained group showed increased reduced glutathione (GSH) content and reduced/oxidized (GSH/GSSG) ratio, higher superoxide dismutase (MnSOD) activity, and decreased lipid peroxidation in liver mitochondria. Aerobic training protected against exhaustive swimming ROS production herein characterized by decreased oxidative stress markers, higher antioxidant defenses, and increases in methyl-tetrazolium reduction and membrane potential. Trained group also presented higher time to exhaustion compared to control group.
  
  
  CONCLUSIONS
  Swimming training induced positive adaptations in liver mitochondria of rats. Increased antioxidant defense after training coped well with exercise-produced ROS and liver mitochondria were less affected by exhaustive exercise. Therefore, liver mitochondria also adapt to exercise-induced ROS and may play an important role in exercise performance.
authors: Laboratório de Bioquímica do Exercício, Centro de Educação Física e Desportos, Universidade Federal de Santa Maria (UFSM), Santa Maria, Rio Grande do Sul, Brazil.
authors: Frederico D
authors: FD
authors: Lima
authors: Daniel N
authors: DN
authors: Stamm
authors: Iuri D
authors: ID
authors: Della-Pace
authors: Fernando
authors: F
authors: Dobrachinski
authors: Nélson R
authors: NR
authors: de Carvalho
authors: Luiz Fernando F
authors: LF
authors: Royes
authors: Félix A
authors: FA
authors: Soares
authors: João B
authors: JB
authors: Rocha
authors: Javier
authors: J
authors: González-Gallego
authors: Guilherme
authors: G
authors: Bresciani
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D008297:Male; D053078:Membrane Potential, Mitochondrial; D008930:Mitochondria, Liver / Q000502:physiology*; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010805:Physical Conditioning, Animal; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000378:metabolism; D013550:Swimming / Q000502:physiology*
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species; D013482:Superoxide Dismutase; D005978:Glutathione