Permeability of the mitochondrial membrane to bicarbonate ions

Osmotic-swelling techniques show that HCO3- enters mitochondria by an electrogenic process, effectively HCO3- uniport, under non-energized conditions. This mode of translocation accounts for previous reports of non-entry of HCO3- in experiments with energy-linked Ca2+ uptake. The effects of HCO3- on mitochondrial respiration are reported and discussed.