Figure 6.
Calcium decreases mitochondrial bioenergetics in a time-dependent manner. Mitochondria (25 μg) were co-incubated with calcium after the addition of the complex I substrates (pyruvate and malate) for increasing amounts of time (1–6 min). An increase in the nmol of oxygen consumed upon addition of calcium was observed, while State III (ADP) driven respiration was inhibited with longer incubations with calcium (25 nmols/mg mitochondrial protein = 2.5 μM). When a higher concentration of calcium was added (100 nmols/mg mitochondrial protein = 10 μM), the inhibitory effect was more pronounced. However, as seen previously in Figure 5, calcium did not affect the complex II (Succinate) driven oxygen consumption. n = 2 per group.