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Endurance training does not affect diaphragm mitochondrial respiration.
- Source :
-
Respiration physiology [Respir Physiol] 1987 Feb; Vol. 67 (2), pp. 225-37. - Publication Year :
- 1987
-
Abstract
- We sought to determine if chronic endurance training would increase mitochondrial respiration or protein content in rat diaphragm muscle. To this end, 20 male Wistar rats were randomly assigned to control (C) or an 8-week endurance training (T) group, n = 10 per group. At the end of T, VO2 max was 13% greater in T (83.3 vs 73.8 ml X kg-1 X min-1) and peak max power output was 32% greater (2.63 vs 1.98 kg X m X min-1). Mitochondrial specific activities of pyruvate-malate and cytochrome oxidase (expressed per mg mitochondrial protein) in both plantaris and diaphragm were similar in C and T rats, as were ADP/O and respiratory control ratios. When expressed per gram wet weight, whole muscle homogenate oxygen uptake (pyruvate + malate) and cytochrome oxidase activity increased 36 and 23%, respectively (P less than 0.05) in plantaris from T rats but did not change in diaphragm. Control oxidative capacity and mitochondrial protein content in the diaphragm were ca. 2-fold those in control plantaris. Plantaris mitochondrial protein content increased ca. 50% with T while the diaphragm was unaffected. We conclude that: plantaris muscle oxidative capacity adapts to training by increasing mitochondrial protein content, since there was no evidence for functional improvement of existing mitochondria, and in the face of a substantial training effect in whole animal and plantaris, the T stimulus was not sufficient to induce mitochondrial protein changes in the diaphragm. This finding is the result of either a 'pre-adaptation' secondary to the diaphragm's high chronic activity, or a sub-threshold increase in diaphragm recruitment during the exercise conditions studied.
- Subjects :
- Alcohol Oxidoreductases metabolism
Animals
Diaphragm enzymology
Diaphragm ultrastructure
Electron Transport Complex IV metabolism
Foot
Male
Mitochondria, Muscle enzymology
Muscle Proteins metabolism
Muscles enzymology
Muscles metabolism
Pyruvate Oxidase metabolism
Rats
Rats, Inbred Strains
Diaphragm metabolism
Mitochondria, Muscle metabolism
Oxygen Consumption
Physical Education and Training
Physical Endurance
Subjects
Details
- Language :
- English
- ISSN :
- 0034-5687
- Volume :
- 67
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Respiration physiology
- Publication Type :
- Academic Journal
- Accession number :
- 3029849
- Full Text :
- https://doi.org/10.1016/0034-5687(87)90043-0