Table 1

Mitochondrial respiratory chain activities

Assays		Patients		Reference value
Assays		4	14	Reference value		30	32	23	34
Flux experiments
Complexes I and III
Pyruvate + malate cytochrome oxidase	0.245	0.327	0.426	0.164	0.418	0.139	0.1–1.0
Glutamate cytochrome reductase	0.009	0.019	0.098	0.147	0.262	0.025	0.1–1.0
Oxoglutarate cytochrome reductase	0.296	0.164	0.426	0.115	0.303	0.115	0.1–1.0
Complexes II and III
Succinate cytochrome reductase	0.475	0.139	0.672	0.409	0.409	0.254	0.1–6.0
Complex IV
Cytochrome oxidase	0.395	0.299	0.901	0.655	0.984	0.59	0.1–5.0

Specific assays
Complex I			0.836	0.409	0.861	0.091	0.1–1.0
Complex II			4.918	9.835	10.359	1.967	3.0–15.0

Respiratory chain activities expressed as μmol/g/min (rate constant k/g/min for COX). Complexes I and III are specific assays. Patients 4, 14, 30, and 32 have been previously reported.26