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Table 2 Mitochondrial functional indices measured by high-resolution respirometry in homogenates

From: Mitochondrial function in skeletal muscle of patients with protracted critical illness and ICU-acquired weakness

Parameter Per muscle wet weight (pmol/s.mg Ww) Per CS activity (pmol.nkat-1.s-1)
ICU (n = 7) Control (n = 8) P ICU (n = 7) Control (n = 8) P
OXPHOS (3p) 7.6 (5.0–8.8)* 13.9 (11.3–17.9) <0.01 31 (28–36)* 37 (32–74) 0.15
RC capacity (3u) 8.6 (6.7–10.5) 16.4 (13.0–20.6) 0.03 41 (37–44) 42 (37–98) 0.46
Non-mito OCR 0.8 (0.6–1.5) 0.8 (0.6–1.3) 0.91 4 (3–5) 2 (1–4) 0.16
F1FoATPase Absolute 6.1 (4.8–7.6)* 12.6 (9.2–13.0) <0.01 26 (26–30)* 33 (29–49) 0.46
% OXPHOS 81 (77–83)* 84 (80–89) 0.36 81 (77–83)* 84 (80–89) 0.36
Proton leak Absolute 1.3 (1.0–1.4)* 2.2 (1.3–3.6) 0.10 8 (5–9)* 7 (4–11) 0.95
% OXPHOS 19 (17–23)* 16 (11–20) 0.36 19 (17–23)* 16 (11–20) 0.36
Complex I 4.8 (4.0–6.1) 6.7 (5.5–8.6) 0.19 23 (22–35) 23 (18–26) 0.35
Complex II 4.6 (2.9–6,5) 1.5 (0.8–3.8) 0.06 23 (20–28) 8 (3–14) <0.01
Complex III/ GPDH 1.5 (1.1–1.9) 0.8 (0.4–1.3) 0.12 7.4 (6.0–9.3) 1.8 (1.2–3.9) <0.01
Complex IV 15.5 (13.0–19.5) 19.7 (15.3–27.5) 0.30 88 (69–99) 49 (40–113) 0.12
  1. Data presented as median (interquartile range), p value as per Mann–Whitney U test. *N = 5 for ICU patients. GPDH glycerol-3-phosphate dehydrogenase, Non-mito OCR non-mitochondrial oxygen consumption rate, OXPHOS oxidative phosphorylation, RC respiratory chain