Rat liver mitochondria accumulate calcium from the incubation medium both in the presence
of ATP and of succinate with rotenone. Lowering free calcium concentration by means
of EGTA leads to a reduction of maximum transport capacity to less than 25 % of the
total added calcium. Under these conditions addition of oxaloacetate inhibits calcium
uptake, an effect which is blocked by equimolar concentrations of β-hydroxybutyrate.
Oxaloacetate and acetoacetate induce an efflux of previously accumulated mitochondrial
calcium. These effects appear to be independent of free calcium concentration and
of whether the mitochondria were obtained from fed rats or rats fasted for 16 h or
4 days.
Liver Mitochondria
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Calcium Transport
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Oxaloacetate
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Acetoacetate
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β-Hydroxybutyrate
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Pyridine Nucleotides
