l-Lactate metabolism in HEP G2 cell mitochondria due to the l-lactate dehydrogenase determines the occurrence of the lactate/pyruvate shuttle and the appearance of oxaloacetate, malate and citrate outside mitochondria

► The existence of the mitochondrial l-LDH (ml-LDH) in Hep G2 cells is shown. ► ml-LDH metabolizes l-lactate that in distinction with pyruvate enters mitochondria. ► The l-lactate/pyruvate shuttle is reconstructed by which NADH is oxidized. ► Oxaloacetate derived from taken up l-lactate is exported outside mitochondria. ► Mitochondrial l-lactate transport and metabolism play an anaplerotic role.