Table 1. Investigation of respiratory chain complex enzyme activities.

Enzyme or enzyme complex	Enzyme activity in the patient in relation to the protein content (mUnit/mg protein)	Normal range	Enzyme or enzyme complex in relation to the citrate synthase	Enzyme activity in the patient in relation to the citrate synthase (mUnit/mUnit CS)	Normal range
Citrate synthase (CS)	324	166–311
Complex I (CI)	20 ↓	30–84	CI/CS	0.06 ↓	0.17–0.35
Complex I+III (C13)	20 ↓	27–50	C13/CS	0.06 ↓	0.13–0.34
Complex II (CII)	107	53–102	CII/CS	0.33	0.27–0.45
Complex II+III (C23)	73	41–84	C23/CS	0.23	0.16–0.35
Complex III (CIII)	280	230–486	CIII/CS	0.86 ↓	1.10–2.37
Cytochrome c oxidase (COX)	181 ↓	253–560	COX/CS	0.56 ↓	0.78–2.01
Complex V (CV)	104	78–178	CV/CS	0.32 ↓	0.44–0.87
Pyruvate dehydrogenase (PDHC)	7.0	3.8–12.7	PDHC/CS	0.022	0.013–0.043

Results showed a decrease of complex I and cytochrome c oxidase in relation to the protein content. The decrease was even more pronounced when related to the marker enzyme citrate synthase.