Fonction mitochondriale et espèces réactives dérivées de l'oxygène : effets du genre et de l'entraînement en endurance chez le rat Wistar et l'anguille européenne

Abstract : Mitochondrion is the main site of aerobic energy (ATP) and reactive oxygen species (ROS) productions. Mitochondrial function is closely linked to ROS, which, according their rate, can alter or optimize energy efficiency. Structural and functional plasticity of mitochondria is essential to maintain homeostasis in any situation that requires metabolic adjustments as physical exercise. The adaptive mechanisms of mitochondrial function and ROS during training and the impact of gender on these responses are still far from being solved. In this perspective, two animal models (Wistar rat and European eel) were chosen.The effects of endurance training of the same intensity (70% of maximal aerobic speed running or swimming) were studied in Wistar rat and silver European eel. The latter is an enduring species capable of performing a spawning migration of 6000 km and characterized by sexual dimorphism in size. In vitro measurements of oxygen consumption, free radical and ATP productions were carried out simultaneously from heart and skeletal muscle permeabilized fibers. The vulnerability or resistance of the mitochondrial function to a ROS generating system exposure (mimicking oxidative stress) was also studied.Before training, in rat, female has a mitochondrial function energetically more efficient and more resistant to ROS, whereas in eel, this metabolic and radical profile is observed rather in male. After training, whatever the species, the improved physical performance observed is associated with various metabolic and radical changes which depending on gender and species. In rats, the improving of mitochondrial function translates differently according to gender. In male, training induces improvement in energy efficiency through a better coupling between oxidation and phosphorylation and/or better use of electrons at the respiratory chain level. In female, increasing in ATP production may be related to the increase in mitochondrial oxygen consumption. As in rats, training induces globally in eel an improvement in energy efficiency and resistance of mitochondrial function to ROS, but only in male. All these results show metabolic and radical responses depending on gender. Whatever the species, training seems to be most beneficial in males than in females in terms of mitochondrial energy efficiency and resistance of mitochondrial function to oxidative stress. In the context of eel migration, these adaptations allow to male, largely smaller than female, a higher swim efficiency, allowing their synchronization on breeding site. Interspecific similarities in training response by gender confirm the interest of fish model’s using in the field of exercise physiology.
Document type :
Theses
Complete list of metadatas

Cited literature [100 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-02012420
Contributor : Abes Star <>
Submitted on : Friday, February 8, 2019 - 4:43:05 PM
Last modification on : Saturday, February 9, 2019 - 1:27:42 AM
Long-term archiving on : Thursday, May 9, 2019 - 3:34:18 PM

File

These-2015-SICMA-Aspects_molec...
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-02012420, version 1

Collections

Citation

Firas Farhat. Fonction mitochondriale et espèces réactives dérivées de l'oxygène : effets du genre et de l'entraînement en endurance chez le rat Wistar et l'anguille européenne. Biologie cellulaire. Université de Bretagne occidentale - Brest, 2015. Français. ⟨NNT : 2015BRES0018⟩. ⟨tel-02012420⟩

Share

Metrics

Record views

154

Files downloads

135