LDH
A ubiquitous enzyme that is a marker of disease and tissue injury.
LDH catalyzes the interconversion of Lactate and pyruvate.
Lactate dehydrogenase activity is present in all tissues.
Lactate dehydrogenase, which catalyzes the bidirectional conversion between lactate and pyruvate, is an enzyme tetramer composed of H and M subunits.
Five isoforms of lactate dehydrogenase can be distinguished in the blood on the basis of the composition of the subunits.
Isoform 1 (H4) predominates in cardiac myocytes and erythrocytes, whereas isoform 5 (M4) is found in hepatocytes and skeletal myocytes.
Pyruvate is the final product of glycolysis.
Lactate is used as fuel for tissues under aerobic conditions.
Lactate provides the oxidative and gluconeogenesis substrates required for cellular homeostasis.
Lactate is a major source of fuel for brain metabolism and is supplied locally from aerobic glycolysis or through the peripheral circulation.
That astrocyte-to-neuron lactate-shuttle theoretically suggests astrocytes synthesize lactate and then it is transported to adjacent neurons as metabolic substrate under physiologic or pathologic conditions.