Mitochondrial function and reactive oxygen species : effects of gender and endurance training in Wistar rat and European eel

• Main Author: Farhat, Firas
• Other Authors: Optimisation des régulations physiologiques (ORPHY (EA 4324)), Institut Brestois Santé Agro Matière (IBSAM), Université de Brest (UBO)-Université de Brest (UBO)-Université de Brest (UBO)-Centre Hospitalier Régional Universitaire de Brest (CHRU Brest), Université de Bretagne occidentale - Brest, Christine Moisan
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2015
• Subjects: Wistar rats; European eel; Gender; Fish model; Endurance training; Mitochondrial function; ROS; Rat Wistar; Anguille européenne; Genre; Modèle poisson; Entrainement de type endurance; Fonction mitochondriale; [SDV.BC]Life Sciences [q-bio]/Cellular Biology
• Online Access: https://tel.archives-ouvertes.fr/tel-02012420; https://tel.archives-ouvertes.fr/tel-02012420/document; https://tel.archives-ouvertes.fr/tel-02012420/file/These-2015-SICMA-Aspects_moleculaires_et_cellulaires_de_la_biologie-FARHAT_Firas.pdf

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 ...