Mrnas of enzymes involved in energy metabolism and mtdna are
increased in endurance trained athletes.
Puntschart, A., H. Claassen, K. Jostarndt, H. Hoppeler, R. Billeter.
Department of Anatomy, University of Bern, CH-3000 Bern 9,
Switzerland
APStracts 2:0141C, 1995.
Improvements in endurance capacity by training are associated with
structural and biochemical adaptations of working muscles which
affect the mitochondrial compartment. We have investigated, whether
the 1.8fold higher mitochondrial volume density in a group of
endurance trained athletes compared to untrained subjects was
reflected by higher steady state levels of mRNAs coding for
components of the oxidative phosphorylation pathway using a
quantitative PCR (polymerase chain reaction) approach. We found that
mitochondrially encoded RNAs (cytochrome c oxidase subunit I (COX1),
NADH reductase subunit 6 (NADH6), 16S rRNA (16S)) as well as nuclear
encoded RNAs (cytochrome c oxidase subunit IV (COX4), succinate
dehydrogenase (SDH), fumarase (Fum)) are all increased coordinately
in the athletes (1.54-1.94 fold). In addition, mitochondrial DNA
(mtDNA) concentration was also 1.55 fold higher in the trained,
whereas genomic DNA was not changed.Our findings thus show similar
RNA expression of mitochondrially encoded genes in sedentary and
endurance trained subjects, while pretranslational control mechanisms
account for higher levels of nuclear encoded RNAs in the athletes.
Received 5 October 1994; accepted in final form 1 March 1995.
APS Manuscript Number C598-4.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 28 March 1995.