Garcia-Souza 2017 MiP2017
Peripheral-blood mononuclear cells (PBMC) and platelets (PLT) are potentially powerful models for the diagnosis of mitochondrial respiratory function and dysfunction, offering a minimally invasive approach in comparison to tissue biopsies. However, several variables that may interfere with mitochondrial physiology in blood cells are still unsolved. High altitude acclimatizaton induces whole body alterations due to low atmospheric oxygen levels and cold temperatures. A decrease of plasma volume, increase in arterial blood pressure and red blood cell count are some of the acclimatizations at altitude [1,2]. However, mitochondrial function of PBMC and PLT at short-term exposure to moderate altitude was never addressed. The objective of our study was the analysis of mitochondrial function of PBMC and PLT after a transition of healthy subjects to 2020 m altitude for 48 h.
Blood was collected from seven healthy female volunteers (26.3 ± 5.7 years) at low altitude of 575 m (Innsbruck, Austria) for 4 days and exposed to an altitude of 2020 m (Kühtai, Austria) for 2 days. During the study, the participants were under a controlled diet and physical activity restricted to a light 1-h walk per day. Every morning at fasted state, blood was taken (18 mL) from up to 4 participants for measurements of respiration in freshly isolated blood cells. PBMC and PLT were separated from whole blood by centrifugation in Ficoll-Paque™ PLUS density medium using 50 mL Leucosep tubes . After the first washing of the PBMC-PLT layer with DPBS (25 mL, 120 g, RT), the PBMC were washed two times with ice-cold DPBS+2% FBS (50 mL, 300 g, 4 °C). Isolated cells were counted with a SYSMEX XN-350 haematology analyser. 3·106 PBMC or 150·106 PLT were added into the 2 mL chambers of the O2k-FluoRespirometer (Oroboros Instruments, Austria) containing mitochondrial respiration medium MiR05-Kit with catalase at 37 °C [3,4]. The coupling control & viability protocol (CCVP) was applied. Respiration of PBMC was corrected for the contribution by contaminating platelets.
PBMC showed a ROUTINE respiration of 5.0 amol·s-1·cell-1 at 575 m and 5.2 amol·s-1·cell-1 at 2020 m. ET capacity was 18.8 amol·s-1·cell-1 (575 m) and 17.4 amol·s-1·cell-1 (2020 m). PLT showed a ROUTINE respiration of 0.12 amol·s-1·cell-1 at 575 m and 0.11 amol·s-1·cell-1 at 2020 m. ET capacity was 0.34 amol·s-1·cell-1 (575 m) and 0.31 amol·s-1·cell-1 (2020 m). There were no significant differences at altitude in PBMC and PLT. Flux control ratios in both cell types were not affected by altitude and cell viability was not compromised at altitude during sample transport to Innsbruck: viability was 94% and 93.3% in PBMC and 92.2% and 90.5% in PLT (575 m and 2020 m, respectively).
In summary, PBMC and PLT respiration was not affected during the first 48 h at altitude. Our results suggest that short-term expsure to mild altitude is not a variable which interferes with mitochondrial functional diagnostics in pathological states. However, longer exposure to altitude and the effect of higher altitude exposure should be investigated.
• Bioblast editor: Kandolf G • O2k-Network Lab: AT Innsbruck Oroboros, SK Bratislava Sumbalova Z, AT Innsbruck Burtscher M, CH Zurich Lundby C, CH Zurich University of Zurich Physiology, DK Copenhagen Lundby C
Affiliations and support
- Garcia-Souza Luiz F(1,2), Cizmarova B(2,3), Sumbalova Z(2,4), Menz V(1), Gatterer H(1), Volani C(5), Lundby C(6), Burtscher M(1), Gnaiger E(2,7)
- Inst Sport Science, Univ Innsbruck, Austria
- Daniel Swarovski Research Lab, Dept Visceral, Transplant Thoracic Surgery, Medical Univ Innsbruck, Austria
- Dept Medical Clinical Biochem, Fac Medicine, Pavol Jozef Šafárik Univ Košice, Slovakia
- Pharmacobiochemical Lab, 3rd Dept Internal Medicine, Fac Medicine, Comenius Univ, Bratislava, Slovakia
- Dept Internal Medicine II, Medical Univ Innsbruck, Austria
- Center Physical Activity Research, Univ Hospital Copenhagen, Denmark
- Oroboros Instruments, Innsbruck, Austria. – [email protected]
- Supported by K-Regio project MitoFit (GSLF, ZS, VM) and Action Austria-Slovakia (BV). Contribution to European Union Framework Programme Horizon 2020 COST Action CA15203 MitoEAGLE.
- Siebenmann C, Robach P, Lundby C (2017) Regulation of blood volume in lowlanders exposed to high altitude. J Appl Physiol, jap-00118.
- Mazzeo RS (2008) Physiological responses to exercise at altitude. Sports Med 38:1-8.
- Garcia-Souza LF, Cizmarova B, Sumbalova Z, Menz V, Burtscher M, Gnaiger E (2017) Assessment of mitochondrial respiratory function in cryopreserved platelets. Abstract, MiPschool Obergurgl 2017.
- Sumbalova Z, Hiller E, Chang S, Garcia L, Droescher S, Calabria E, Volani C, Krumschnabel G, Gnaiger E (2016) Isolation of blood cells for HRR. Mitochondr Physiol Network 21.17:1-15.
Labels: MiParea: Respiration
Organism: Human Tissue;cell: Blood cells, Platelet
Coupling state: ROUTINE, ET