Mitochondria and l-lactate metabolism

Abstract 

Although mitochondria have been the object of intensive study over many decades, some aspects of their metabolism remain to be fully elucidated, including the l-lactate metabolism.

We review here the novel insights arisen from investigations on l-lactate metabolism in mammalian, plant and yeast mitochondria. The presence of l-lactate dehydrogenases inside mitochondria, where l-lactate enters in a carrier-mediated fashion, suggests that mitochondria play an important role in l-lactate metabolism. Functional studies have demonstrated the occurrence of several l-lactate carriers. Moreover, immunological investigations have proven the existence of monocarboxylate translocator isoforms in mitochondria.

Abbreviations: cL-LDH, cytosolic l-lactate dehydrogenase, COX, cytochrome c oxidase, GNG, gluconeogenesis, l-LAC, l-lactate, mL-LDH, mitochondrial l-lactate dehydrogenase, MCT, monocarboxylate transporter, MCT1, monocarboxylate transporter isoform 1, MCT2, monocarboxylate transporter isoform 2, MPC, mitochondrial pyruvate carrier, OAA, oxaloacetate, PYR, pyruvate, RHM, rat heart mitochondria, RLM, rat liver mitochondria

Keywords: l-Lactate, Metabolism, Mitochondria, Mitochondrial transport, Dehydrogenase