Item request has been placed! ×
Item request cannot be made. ×
loading  Processing Request

Abnormalities of mitochondrial functioning can partly explain the metabolic disorders encountered in sarcopenic gastrocnemius.

Item request has been placed! ×
Item request cannot be made. ×
loading   Processing Request
  • معلومة اضافية
    • Contributors:
      Unité de nutrition lipidique; Institut National de la Recherche Agronomique (INRA); Bioénergétique fondamentale et appliquée; Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de la Santé et de la Recherche Médicale (INSERM); Métabolisme protéino-énergétique (UMPE); Institut National de la Recherche Agronomique (INRA)-Université d'Auvergne - Clermont-Ferrand I (UdA); Laboratoire de Physiopathologie et de Pharmacologie Cardiovasculaire Expérimentale (LPPCE); Université de Bourgogne (UB)
    • بيانات النشر:
      CCSD
      Wiley Open Access
    • الموضوع:
      2007
    • Collection:
      Université de Bourgogne (UB): HAL
    • نبذة مختصرة :
      International audience ; Aging triggers several abnormalities in muscle glycolytic fibers including increased proteolysis, reactive oxygen species (ROS) production and apoptosis. Since the mitochondria are the main site of substrate oxidation, ROS production and programmed cell death, we tried to know whether the cellular disorders encountered in sarcopenia are due to abnormal mitochondrial functioning. Gastrocnemius mitochondria were extracted from adult (6 months) and aged (21 months) male Wistar rats. Respiration parameters, opening of the permeability transition pore and ROS production, with either glutamate (amino acid metabolism) or pyruvate (glucose metabolism) as a respiration substrate, were evaluated at different matrix calcium concentrations. Pyruvate dehydrogenase and respiratory complex activities as well as their contents measured by Western blotting analysis were determined. Furthermore, the fatty acid profile of mitochondrial phospholipids was also measured. At physiological calcium concentration, state III respiration rate was lowered by aging in pyruvate conditions (-22%), but not with glutamate. The reduction of pyruvate oxidation resulted from a calcium-dependent inactivation of the pyruvate dehydrogenase system and could provide for the well-known proteolysis encountered during sarcopenia. Matrix calcium loading and aging increased ROS production. They also reduced the oxidative phosphorylation. This was associated with lower calcium retention capacities, suggesting that sarcopenic fibers are more prone to programmed cell death. Aging was also associated with a reduced mitochondrial superoxide dismutase activity, which does not intervene in toxic ROS overproduction but could explain the lower calcium retention capacities. Despite a lower content, cytochrome c oxidase displayed an increased activity associated with an increased n-6/n-3 polyunsaturated fatty acid ratio of mitochondrial phospholipids. In conclusion, we propose that mitochondria obtained from aged muscle fibers display several ...
    • Relation:
      info:eu-repo/semantics/altIdentifier/pmid/17286611; PRODINRA: 249670; PUBMED: 17286611
    • الرقم المعرف:
      10.1111/j.1474-9726.2007.00271.x
    • الدخول الالكتروني :
      https://inserm.hal.science/inserm-00388555
      https://inserm.hal.science/inserm-00388555v1/document
      https://inserm.hal.science/inserm-00388555v1/file/2007_Martin_Aging%20Cell_1.pdf
      https://doi.org/10.1111/j.1474-9726.2007.00271.x
    • Rights:
      http://creativecommons.org/licenses/by/ ; info:eu-repo/semantics/OpenAccess
    • الرقم المعرف:
      edsbas.82D9FBED