Etude comparative de la relation entre espèces réactives

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Ecole doctorale SICMA 0373
Thèse de doctorat de l’Université de Bretagne Occidentale
Spécialité : Science de la Vie-Physiologie
Orphy
EA-4324
Par MORTELETTE HELENE
Etude comparative de la relation entre espèces
réactives dérivées de l’oxygène et
métabolisme musculaire : effets de l’entraînement
Soutenance prévue le 3 décembre 2010
Rapporteurs :
M Jean-Jacques Risso, Directeur de recherches, IRBA, Institut de Médecine Navale du service de
santé des Armées, Toulon
M Felix Mark, Chercheur associé, AWI, Alfred Wegener Institut für Polar, Bremerhaven
Examinateurs
Mme Moisan Christine, Professeur des universités, EA ORPHY, UBO, Brest ; Directrice de thèse
Mlle Amérand Aline, Maître de conférences, EA ORPHY, UBO, Brest ; co-encadrante
M Claireaux Guy, Professeur des universités, EA ORPHY, UBO, Brest
M McKenzie David, Chargé de recherches CNRS, ISEM, Institut des Sciences et de l’Evolution
Montpellier.
Membre invité
M Sébert Philippe, Maître de conférences, EA ORPHY, UBO, Brest
0,25µm
Micrographie d’une mitochondrie isolée d’anguille argentée (x 60000)
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Abstract
Comparative study of the relationship between reactive oxygen species
(ROS) and muscle metabolism: effects of training
A comparative study of the relationship between ROS production and metabolism was
performed in muscle of animals (fish and mammal) with different metabolic rate. Thus,
interspecific (ectotherm/endotherm) and intraspecific (yellow/silver eel and lean/obese Zucker
rat) comparisons were realized. Effects of training on the ROS/metabolic rate relation and the
radical metabolism (OH• production, anti-oxidants systems, radical attack) were investigated
in these species. European eels were subjected to training sessions at different intensities and
a running protocol (moderate intensity) was used for Zucker rat. The effects of training in eel
were analyzed in the spawning migration context.
The positive correlation between OH• production and metabolic rate (MO2) obtained in vitro
on permeabilized muscle fibers, was confirmed in all animals. Training induced different
changes in this relation but independently of the quality of endotherm or ectotherm. Indeed,
radical production linked to mitochondrial functioning (OH•/MO2) is an interesting index of
training metabolic effects (stimulation of aerobic and/or anaerobic pathways). Two metabolic
responses were observed: (1) with moderate intensity training (silver eels, lean and obese
Zucker rat), the stability or the decrease in the OH•/MO2 ratio is accompanied by an increased
aerobic capacity and probably by an improvement of the oxidative phosphorylation, (2) with a
more intensive training (yellow and silver eels), the enhancement in OH•/MO2 ratio is
accompanied by a decrease in aerobic capacity compensated by an increase in anaerobic
capacity and by an oxidative stress (yellow eel).
In the spawning migration context, silver eels subjected to a moderate intensity training,
increases their swimming performance by an improvement of the mitochondrial function and
of the aerobic capacity. These swimming conditions appear optimal for spawning migration.
But, in yellow or silver eels subjected to a more intensive training, the metabolic responses
reflect an overtraining state (stimulation of anaerobic metabolism and free radical production)
despite the increase in swimming performance.