Table 4.
Electron Transport Chain (ETC) Activity in Fibroblasts and Skeletal Muscle*
| Complexes; enzymatic activity, units below (% of mean) |
||||||||
|---|---|---|---|---|---|---|---|---|
| Tissue | Patient | I-III | “I” | II-III | “II” | III | IV | CS |
| FB | S1 | 10.5 (50%) |
25.9 (101%) |
5.8 (181%) |
72.0 (90%) |
1.3 (65%) |
43.0 (82%) |
|
| FB control |
Mean ± SD (n=144) |
20.9 ± 10.9 | 25.6 ± 4.5 | 3.2 ± 0.8 | 79.8 ± 17.7 | 2.0 ± 0.3 | 52.2 ± 8.8 | |
| Range | 6.1–50.8 | 17.1–33.6 | 1.9–4.3 | 49.7–116.7 | 1.5–2.6 | 36.3–69.9 | ||
| FB | S2 | ND | ND | 16.7 (246%) |
ND | 80.1 (46%) |
1.0 (91%) |
52.5 (122%) |
| FB control |
Mean ± SD (29) |
6.8 ± 3.7 | 173.2 ± 76.7 | 1.1 ± 0.4 | 42.9 ± 10.4 | |||
| Range | 3.6–20.3 | 37.5–311.0 | 0.6–2.5 | 22.9–63.3 | ||||
| SM | S1 |
0.3 (25%) |
48.5(162%) | 1.1 (52%) |
1.2 150%) |
16.9 (111%) |
64.5 (43%) |
12.5 (67%) |
| S2 |
0.4 (33%) |
25.3 (85%) |
0.4 (19%) |
0.5 (63%) |
5.8 (38%) | 61.6 (41%) |
24.5 (132%) |
|
| SM control |
Mean ± SD (n=49) |
1.2 ± 1.1 | 29.9 ± 12.9 | 2.1 ± 1.2 | 0.8 ± 0.4 | 15.2 ± 6.8 | 148.9 ± 67.2 | 18.6 ± 4.7 |
| Range | 0.2–4.7 | 11.5–60.1 | 0.4–4.9 | 0.1–2.0 | 6.8–35.2 | 57.3–373.0 | 9.4–30.0 | |
Oxidative phosphorylation (OxPhos, integrated function) assayed in intact and permeabilized fibroblasts in both sibs were normal (data not shown); Enzyme activity: FB, nmol/min/mg protein and SM, µmol/min/g wet weight. I-III, NADH-cytochrome c reductase (rotenone sensitive); “I”, NADH-ferricyanide reductase; II-III, succinate-cytochrome c reductase (antimycin sensitive); “II”, succinate dehydrogenase; III, decylubiquinol-cytochrome c reductase; IV, cytochrome c oxidase; CS, citrate synthase; ND, not done; and SD: standard deviation. Low CIII in SM of S2 is shown in bold and red. Other SM ETC activities at the low end of the reference range in S1 and S2 are shown in bold and blue. FB ETC assays of S1 and S2 were as previously described [19] and 20], respectively.