title: Rapid down-regulation of mitochondrial fat metabolism in human muscle after training cessation is dissociated from changes in insulin sensitivity.
abstract: The association between impairment in mitochondrial muscle fat oxidative capacity (OX(FA)) and occurrence of insulin resistance was examined in 14 healthy trained men (age, 24+/-4 yr) submitted to 4 weeks of training cessation. Training stop induced a significant decrease in mRNA levels of proteins involved in muscle fat metabolism, particularly PPARalpha (-58%, P<0.01) and PGC-1alpha (-30%, P<0.05), a 21% reduction in OX(FA) (P<0.01), and reduced fat oxidation during moderately intense exercise (P<0.05). In contrast, there was no significant alteration in insulin sensitivity. In conclusion, decline in OX(FA) is a rapid metabolic event following training cessation. It is involved in the regulation of whole body fat balance but not in the deterioration of insulin sensitivity.
authors: INRA, UMR1019 Human Nutrition, F-63120 Saint-Genès-Champanelle, France.
authors: Virginie
authors: V
authors: Rimbert
authors: Hubert
authors: H
authors: Vidal
authors: Pascale
authors: P
authors: Duché
authors: Cyrille
authors: C
authors: Debard
authors: Christophe
authors: C
authors: Giraudet
authors: Yves
authors: Y
authors: Boirie
authors: Jean-Michel
authors: JM
authors: Chardigny
authors: Béatrice
authors: B
authors: Morio
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D001823:Body Composition; D015536:Down-Regulation; D015444:Exercise; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D050356:Lipid Metabolism; D008297:Male; D008931:Mitochondria, Muscle / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism*; D010084:Oxidation-Reduction; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D007328:Insulin