Pesta 2010 MiP Abstract
Pesta D, Faulhaber M, Burtscher M, Gnaiger E, Schocke M (2010) Investigation of muscle metabolism of the M. quadriceps via 31P MRS and high-resolution respirometry in connection with 10 weeks of strength and endurance training in normoxia and hypoxia. MiP2010. |
Link: Abstracts Session 2
Pesta D, Faulhaber M, Burtscher M, Gnaiger E, Schocke M (2010)
Event: MiP2010
Skeletal muscle is a highly adaptable tissue that can adjust to different external stimuli [1,2]. In the present study we investigated the impact of altered environmental conditions (normoxia and hypoxia) as well as training regimes (strength and endurance training) on parameters of muscle metabolism including mitochondrial respiration (OXPHOS and ET-pathway capacities) with different substrates and substrate combinations.
β’ O2k-Network Lab: AT Innsbruck Oroboros, AT Innsbruck Burtscher M
Full text
Skeletal muscle is a highly adaptable tissue that can adjust to different external stimuli [1,2]. In the present study we investigated the impact of altered environmental conditions (normoxia and hypoxia) as well as training regimes (strength and endurance training) on parameters of muscle metabolism including mitochondrial respiration (OXPHOS and ET-pathway capacities) with different substrates and substrate combinations.
For assessing these parameters, 40 healthy and not specifically trained subjects enrolled in a strength and endurance training program lasting for 10 weeks, and split into a normoxic and a normobaric intermittent hypoxic (FiO2=0.12) training group. At baseline, subjects performed an in-vivo phosphorus-31 magnetic resonance spectroscopy (31P MRS) test of the quadriceps muscles during dynamic leg-extension exercise [3]. Subsequently, endurance and strength capacities of the subjects were determined via motor performance tests. Biopsy samples from the vastus lateralis were obtained from the subjects for fibre type distribution with ATPase staining and measurement of mitochondrial performance with high-resolution respirometry to examine oxidative capacity of the muscle tissue [4,5]. After 10 weeks, the initial tests and muscle biopsies were repeated.
The Figure [5] shows superimposed traces of oxygen flux per mg tissue wet weight, from two subsamples of the same subject (Oroboros Oxygraph-2k; 37 Β°C; MiR06 [6]; [O2] above 220 Β΅M and below 360 Β΅M with intermittent reoxygenations). The additive effect of CI+II substrate combinations [4] was pronounced, and an increase of [ADP] from 2.5 to 5.0 mM stimulated respiration significantly, thus reducing the apparent limitation by the phosphorylation system (stimulation by FCCP titration to induce the non-coupled state of electron transport system (ET-pathway) capacity. Residual oxygen consumption (ROX) is overestimated after short periods of inhibition of CII and CIII, with a further decline proceeding gradually as in the case of inhibition of CII in the presence of succinate. Our results will permit to evaluate physiological, biochemical, and molecular responses to a change in muscle metabolism resulting from a normoxic and hypoxic training regime.
Supported by OeNB JubilΓ€umsfond Austria project 13476; contribution to Mitofood COST Action FAO602.
1. Desplanches D, Hoppeler H, TΓΌscher L, Mayet MH, Spielvogel H, Ferretti G, et al. (1996) Muscle tissue adaptations of high-altitude natives to training in chronic hypoxia or acute normoxia. J Appl Physiol 81:1946-51.
2. Hoppeler H, Klossner S, Vogt M (2008) Training in hypoxia and its effects on skeletal muscle tissue. Scand J Med Sci Sports 18 Suppl 1:38-49.
3. Schocke MF, Esterhammer R, Arnold W, Kammerlander C, Burtscher M, Fraedrich G, et al. (2005) High-energy phosphate metabolism during two bouts of progressive calf exercise in humans measured by phosphorus-31 magnetic resonance spectroscopy. Eur J Appl Physiol 93:469-79.
Labels: MiParea: Respiration, mt-Biogenesis;mt-density, Exercise physiology;nutrition;life style
Pathology: Obesity
Stress:Ischemia-reperfusion
Organism: Human
Coupling state: LEAK, OXPHOS, ET
Pathway: F, N, S, NS
HRR: Oxygraph-2k