Figure 3.

Ca²⁺uptake does not increase liver mitochondrial oxidative phosphorylation supported by succinate. Isolated mouse liver mitochondria (200 μg) were energized with 1 mM succinate in the presence of 1 μM rotenone. A, representative Ca²⁺ uptake curves using Ca²⁺Green 5N to measure extramitochondrial Ca²⁺ in the presence of low Ca²⁺ (2.4 ± 0.6 μM, gray line), medium Ca²⁺ (22.0 ± 2.4 μM, blue line), and high Ca²⁺ (52.9 ± 2.5 μM, purple line). B–E, representative OCR traces in response to zero Ca²⁺ (B), low Ca²⁺ (C), medium Ca²⁺ (D), and high Ca²⁺ (E), followed by injection of 1 mM ADP, 1 μM oligomycin (oligo), and 0.5 μM CCCP. F, state 3, after ADP addition. F = 1.784, p = 0.2651. G, state 4, after oligomycin addition. F = 5.792, p = 0.0481, ∗p = 0.0159 versus zero Ca²⁺. H, maximal respiration after CCCP addition. F = 0.6058, p = 0.5579. I, respiratory control ratios (RCR, state 3/state 4). F = 1.654, p = 0.2805. n = 4 independent experiments; one-way ANOVA followed by Šidak.