Table 1.

Baseline liver mitochondrial respiratory chain complexes activities and mitochondrial coupling.

Control	Young (3 months)	Middle-aged (18 months)
V max⁡ (µmol O2/min/g protein)	29.8 ± 5.6	30.0 ± 1.6
V succ (µmol O2/min/g protein)	35.0 ± 3.7	33.9 ± 1.7
V tmpd (µmol O2/min/g protein)	50.0 ± 6.2	43.0 ± 1.6
ACR	9.7 ± 2.6	10.5 ± 1.3

Data are means ± SEM.

ACR: acceptor control ratio (V _max⁡/V ₀).