title: Mitochondrial coupling and capacity of oxidative phosphorylation in skeletal muscle of Inuit and Caucasians in the arctic winter.
abstract: During evolution, mitochondrial DNA haplogroups of arctic populations may have been selected for lower coupling of mitochondrial respiration to ATP production in favor of higher heat production. We show that mitochondrial coupling in skeletal muscle of traditional and westernized Inuit habituating northern Greenland is identical to Danes of western Europe haplogroups. Biochemical coupling efficiency was preserved across variations in diet, muscle fiber type, and uncoupling protein-3 content. Mitochondrial phenotype displayed plasticity in relation to lifestyle and environment. Untrained Inuit and Danes had identical capacities to oxidize fat substrate in arm muscle, which increased in Danes during the 42 days of acclimation to exercise, approaching the higher level of the Inuit hunters. A common pattern emerges of mitochondrial acclimatization and evolutionary adaptation in humans at high latitude and high altitude where economy of locomotion may be optimized by preservation of biochemical coupling efficiency at modest mitochondrial density, when submaximum performance is uncoupled from VO2max and maximum capacities of oxidative phosphorylation.
authors.affiliation: Department of Visceral, Transplant and Thoracic Surgery, D. Swarovski Research Laboratory, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: E
authors.initials: E
authors.lastname: Gnaiger
authors.affiliation: The Copenhagen Muscle Research Centre, Copenhagen, Denmark.|School of Kinesiology, University of British Columbia, Vancouver, BC, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Boushel
authors.affiliation: The Copenhagen Muscle Research Centre, Copenhagen, Denmark.
authors.forename: H
authors.initials: H
authors.lastname: Søndergaard
authors.affiliation: The Copenhagen Muscle Research Centre, Copenhagen, Denmark.
authors.forename: T
authors.initials: T
authors.lastname: Munch-Andersen
authors.affiliation: The Copenhagen Muscle Research Centre, Copenhagen, Denmark.
authors.forename: R
authors.initials: R
authors.lastname: Damsgaard
authors.affiliation: National Serum Institute, Copenhagen, Denmark.
authors.forename: C
authors.initials: C
authors.lastname: Hagen
authors.affiliation: Department of Biochemistry and Molecular and Cell Biology, University of Zaragoza, Zaragoza, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Díez-Sánchez
authors.affiliation: GENUD Toledo Research Group, University of Castilla-La Mancha, Toledo, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Ara
authors.affiliation: Department of Exercise Science, Concordia University, Montreal, QC, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Wright-Paradis
authors.affiliation: NUTRIM - School for Nutrition, Toxicology and Metabolism, Department of Human Biology, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: P
authors.initials: P
authors.lastname: Schrauwen
authors.affiliation: NUTRIM - School for Nutrition, Toxicology and Metabolism, Department of Human Biology, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Hesselink
authors.affiliation: Department of Physical Education, Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Las Palmas, Spain.
authors.forename: J A L
authors.initials: JA
authors.lastname: Calbet
authors.affiliation: National Serum Institute, Copenhagen, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Christiansen
authors.affiliation: The Copenhagen Muscle Research Centre, Copenhagen, Denmark.|X-Lab, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: J W
authors.initials: JW
authors.lastname: Helge
authors.affiliation: The Copenhagen Muscle Research Centre, Copenhagen, Denmark.
authors.forename: B
authors.initials: B
authors.lastname: Saltin
mesh_terms: D000255:Adenosine Triphosphate / Q000096:biosynthesis; D000328:Adult; D019069:Cell Respiration; D003080:Cold Temperature; D004272:DNA, Mitochondrial; D057645:Deltoid Muscle / Q000166:cytology / Q000378:metabolism*; D003718:Denmark / Q000208:ethnology; D005227:Fatty Acids / Q000378:metabolism; D005260:Female; D006116:Greenland / Q000208:ethnology; D006239:Haplotypes; D006801:Humans; D004930:Inuit / Q000235:genetics; D007473:Ion Channels / Q000378:metabolism; D008297:Male; D008931:Mitochondria, Muscle / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000378:metabolism; D010084:Oxidation-Reduction; D010085:Oxidative Phosphorylation; D010101:Oxygen Consumption; D052097:Quadriceps Muscle / Q000166:cytology / Q000378:metabolism*; D012621:Seasons; D012865:Skiing / Q000502:physiology; D022722:Thermogenesis; D000071247:Uncoupling Protein 3; D044465:White People / Q000235:genetics
chemical_list: D004272:DNA, Mitochondrial; D005227:Fatty Acids; D007473:Ion Channels; D024101:Mitochondrial Proteins; C000604392:UCP3 protein, human; D000071247:Uncoupling Protein 3; D000255:Adenosine Triphosphate
keywords: Inuit; Mitochondrial haplogroup; proton leak; substrates; thermogenesis