Figure 7. Mitochondrial respiratory chain function from 7-month-old control mice raised in normal litters (NL) and postnatally overfed mice raised in small litters (SL) which, at 6 months of age, were assigned to be fed either ad libitum (AL) or with 20% calorie restriction (CR) for 1 month (4 groups were constituted: NLAL, NLCR, SLAL and SLCR).

(A) Respiratory flux rates of permeabilized cardiac fibers. The respiratory parameters are: State 1, Basal oxygen consumption of mitochondria with endogenous substrates; State 2:, glutamate + malate + pyruvate (substrates-driven respiration through CI); State 2: by adding succinate (substrate-driven respiration through CII); State 3: further adding ADP (maximal substrates-ADP driven respiration: maximal coupled respiration); State 4: inhibition of CV through carboxy-atractyloside, allowing the measurement of non-coupled respiration of coupled mitochondria (maximal leak). (B) Cardiac expression of the five complexes (CI-CV) of the respiratory chain (OXPHOS) as determined by immunoblotting. (C) Representative immunoblotting of protein levels of OXPHOS complexes I-V. Cardiac protein level was normalized to glyceradehyde-3-phosphate dehydrogenase (GAPDH) content and expressed relative to the control (NL) group.