title: Apparent Km of mitochondria for oxygen computed from Vmax measured in permeabilized muscle fibers is lower in water enriched in oxygen by electrolysis than injection.
abstract: BACKGROUND
  It has been suggested that oxygen (O2) diffusion could be favored in water enriched in O2 by a new electrolytic process because of O2 trapping in water superstructures (clathrates), which could reduce the local pressure/content relationships for O2 and facilitate O2 diffusion along PO2 gradients.
  
  
  METHODS
  Mitochondrial respiration was compared in situ in saponin-skinned fibers isolated from the soleus muscles of Wistar rats, in solution enriched in O2 by injection or the electrolytic process 1) at an O2 concentration decreasing from 240 µmol/L to 10 µmol/L (132 mmHg to 5 mmHg), with glutamate-malate or N, N, N', N'-tetramethyl-p-phenylenediamine dihydrochloride (TMPD)-ascorbate (with antimycin A) as substrates; and 2) at increasing adenosine diphosphate (ADP) concentration with glutamate-malate as substrate.
  
  
  RESULTS
  As expected, maximal respiration decreased with O2 concentration and, when compared to glutamate-malate, the apparent Km O2 of mitochondria for O2 was significantly lower with TMPD-ascorbate with both waters. However, when compared to the water enriched in O2 by injection, the Km O2 was significantly lower with both electron donors in water enriched in O2 by electrolysis. This was not associated with any increase in the sensitivity of mitochondria to ADP; no significant difference was observed for the Km ADP between the two waters.
  
  
  CONCLUSIONS
  In this experiment, a higher affinity of the mitochondria for O2 was observed in water enriched in O2 by electrolysis than by injection. This observation is consistent with the hypothesis that O2 diffusion can be facilitated in water enriched in O2 by the electrolytic process.
authors.affiliation: Physiology Department, Faculty of Medicine and EA3072, Université de Strasbourg, Strasbourg, France.
authors.forename: Joffrey
authors.initials: J
authors.lastname: Zoll
authors.affiliation: Physiology Department, Faculty of Medicine and EA3072, Université de Strasbourg, Strasbourg, France.
authors.forename: Jamal
authors.initials: J
authors.lastname: Bouitbir
authors.affiliation: Clermont Université, Université Blaise Pascal, EA 3533, Laboratoire des Adaptations Métaboliques à l'Exercice en Conditions Physiologiques et Pathologiques, Clermont-Ferrand, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Sirvent
authors.affiliation: Danone Research, Centre Daniel Carasso, Palaiseau, France.
authors.forename: Alexis
authors.initials: A
authors.lastname: Klein
authors.affiliation: Physiology Department, Faculty of Medicine and EA3072, Université de Strasbourg, Strasbourg, France ; Department of Anesthesia and Critical Care and EA3072, Hôpital de Hautepierre, Université de Strasbourg, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Charton
authors.affiliation: Danone Research, Centre Daniel Carasso, Palaiseau, France.
authors.forename: Liliana
authors.initials: L
authors.lastname: Jimenez
authors.affiliation: Kinesiology Department, Université de Montréal, Montréal, QC, Canada.
authors.forename: François R
authors.initials: FR
authors.lastname: Péronnet
authors.affiliation: Physiology Department, Faculty of Medicine and EA3072, Université de Strasbourg, Strasbourg, France.
authors.forename: Bernard
authors.initials: B
authors.lastname: Geny
authors.affiliation: Department of Sport Medicine and Functional Explorations and INRA UMR 1019, Faculty of Medicine, Université d'Auvergne, Clermont-Ferrand, France.
authors.forename: Ruddy
authors.initials: R
authors.lastname: Richard
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism; D000818:Animals; D004572:Electrolysis; D018698:Glutamic Acid / Q000378:metabolism; D008293:Malates / Q000378:metabolism; D008297:Male; D008928:Mitochondria / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012503:Saponins / Q000494:pharmacology; D014867:Water / Q000737:chemistry*
chemical_list: D008293:Malates; D012503:Saponins; D014867:Water; D018698:Glutamic Acid; D000244:Adenosine Diphosphate; C030298:malic acid; D010100:Oxygen
keywords: Km O2; TMPD–ascorbate; glutamate–malate; mitochondrial respiration; saponin-skinned fibers