title: mRNAs of enzymes involved in energy metabolism and mtDNA are increased in endurance-trained athletes.
abstract: Improvements in endurance capacity by training are associated with structural and biochemical adaptations of working muscles that affect the mitochondrial compartment. We investigated whether the 1.8-fold higher mitochondrial volume density in a group of endurance-trained athletes compared with untrained subjects was reflected by higher steady-state levels of mRNAs coding for components of the oxidative phosphorylation pathway using a quantitative polymerase chain reaction approach. We found that mitochondrially encoded RNAs (cytochrome-c oxidase subunit I, NADH reductase subunit 6, 16S rRNA), as well as nuclear-encoded RNAs (cytochrome-c oxidase subunit IV, succinate dehydrogenase, fumarase) are all increased coordinately in the athletes (1.54- to 1.94-fold). In addition, mitochondrial (mt) DNA concentration was also 1.55-fold higher in the trained athletes, whereas genomic DNA was not changed. Our findings thus show similar RNA expression of mitochondrially encoded genes in sedentary and endurance-trained subjects, whereas pretranslational control mechanisms account for higher levels of nuclear-encoded RNAs in the athletes.
authors.affiliation: Department of Anatomy, University of Bern, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Puntschart
authors.forename: H
authors.initials: H
authors.lastname: Claassen
authors.forename: K
authors.initials: K
authors.lastname: Jostarndt
authors.forename: H
authors.initials: H
authors.lastname: Hoppeler
authors.forename: R
authors.initials: R
authors.lastname: Billeter
mesh_terms: D000328:Adult; D004272:DNA, Mitochondrial / Q000235:genetics*; D004734:Energy Metabolism; D004798:Enzymes / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D008297:Male; D010807:Physical Endurance; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism*; D013177:Sports / Q000502:physiology*
chemical_list: D004272:DNA, Mitochondrial; D004798:Enzymes; D012333:RNA, Messenger