title: Mitochondrial complex I deficiency and ATP/ADP ratio in lymphocytes of amyotrophic lateral sclerosis patients.
abstract: OBJECTIVE
  Several lines of evidence suggest that mitochondrial dysfunction is involved in amyotrophic lateral sclerosis (ALS), but despite the fact that mitochondria play a central role in excitotoxicity, oxidative stress, and apoptosis, the intimate underlying  mechanism linking mitochondrial defects to motor neuron degeneration in ALS still remains elusive. This study was performed to assess the mitochondrial respiratory chain dysfunction and cellular energy index (ATP/ADP ratio) in lymphocytes of ALS patients.
  
  
  METHODS
  In this study,  activity of mitochondrial respiratory chain complex I (measured as NADH-ferricyanide reductase) and both intracellular ATP and ADP measurements were performed on lymphocytes of ALS patients (n = 14) and control subjects (n = 26). Then, ATP/ADP ratio was calculated.
  
  
  RESULTS
  Our finding showed that in patients compared with controls, complex I activity and intracellular ATP were significantly reduced (P = 0·001) and intracellular ADP content was increased (P<0·005) and ATP/ADP ratio subsequently was decreased and also we  found strong correlation between complex I activity and intracellular ATP content and strong reverse correlation between complex I activity and intracellular ADP content in the patients with ALS (r(2) = 0·90).
  
  
  CONCLUSIONS
  This study suggests that  complex I deficiency and both reduction in intracellular ATP and increase in intracellular ADP content may be involved in the progression and pathogenesis of ALS.
authors.affiliation: Department of Biochemistry, Tarbiat Modares University, Tehran, Iran.
authors.forename: Parisa
authors.initials: P
authors.lastname: Ghiasi
authors.forename: Saman
authors.initials: S
authors.lastname: Hosseinkhani
authors.forename: Alireza
authors.initials: A
authors.lastname: Noori
authors.forename: Shahriar
authors.initials: S
authors.lastname: Nafissi
authors.forename: Khosro
authors.initials: K
authors.lastname: Khajeh
mesh_terms: D000244:Adenosine Diphosphate / Q000032:analysis / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000032:analysis / Q000378:metabolism*; D000328:Adult; D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000378:metabolism*; D042967:Electron Transport Complex I / Q000172:deficiency*; D005260:Female; D006801:Humans; D008214:Lymphocytes / Q000737:chemistry / Q000378:metabolism*; D008297:Male; D008875:Middle Aged
chemical_list: D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D042967:Electron Transport Complex I