Table 2.
Results of the mitochondrial enzyme diagnostics.
| Activity | Control range | Unit | |
|---|---|---|---|
| Substrate oxidation rates | |||
| 1. [1-14C] pyruvate+ malate | 0.74 | 3.61–7.48 | nmolCO2/h.mUCS |
| 2. [1-14C] pyruvate + carnitine | 1.18 | 2.84–8.24 | nmolCO2/h.mUCS |
| 3. [U-14C] malate + pyruvate + malonate | 0.80 | 4.68–9.62 | nmolCO2/h.mUCS |
| 4. [U-14C] malate + acetylcarnitine + malonate | 1.15 | 3.43–9.62 | nmolCO2/h.mUCS |
| 5. [U-14C] malate + acetylcarnitine + arsenite | 0.93 | 2.05–3.85 | nmolCO2/h.mUCS |
| 6. [1,4-14C] succinate + acetlycarnitine | 0.70 | 2.54–6.39 | nmolCO2/h.mUCS |
| ATP metabolism | |||
| ATP + CrP production pyruvate | 7.6 | 42.1–81.2 | nmol/h.mUCS |
| Enzyme activities | |||
| Complex I | 20 | 70–251 | mU/UCS |
| Complex II | 291 | 335–749 | mU/UCS |
| Complex III | 1,523 | 2,200–6,610 | mU/UCS |
| Complex II + III (Succ.: cyt.c oxidoreductase; SCC) | 222 | 300–970 | mU/UCS |
| Complex IV | 825 | 810–3,120 | mU/UCS |
| Complex V (ATPase) | 345 | 169–482 | mU/UCOX |
| Citrate synthase | 37 | 37.4–162 | mU/mg |
Oxidation rates for 14C-labeled substrates were calculated as nmol 14CO2/(h · mU CS). The ATP production rate was calculated as nmol (ATP + CrP)/(h mU CS). Complex I activity was expressed as mU/U complex II, mU/U complex IV, or U/g protein, in which 1 U complex I activity equals 1 μmol DCIP reduced per min. The activity of complex I is significantly reduced in patient I's muscle. Complex II, III, II + III activity is also reduced.