Lactate Dehydrogenase is an enzyme found in many tissues in the body, including the heart, liver, and muscles. High levels of LDH can indicate tissue damage or certain types of cancer.
Alanine is converted to pyruvate which can be reduced to lactate by lactate dehydrogenase (LDH). Elevated alanine levels may reflect increased LDH activity.
Koukourakis MI, Pitiakoudis M, Giatromanolaki A, Tsarouha A, Polychronidis A, Sivridis E, Simopoulos C. A new parameter using serum lactate dehydrogenase and alanine aminotransferase level is useful for predicting the prognosis of acute liver injury. Cancer Science (2008). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2527551/
Glutamate dehydrogenase, which interconverts glutamate and alpha-ketoglutarate, is linked to the activity of lactate dehydrogenase via the citric acid cycle. Elevated glutamate may indirectly reflect increased LDH.
H. Hertz, L. Chen, and M. Chen. “Dysfunctional TCA-Cycle Metabolism in Glutamate Dehydrogenase siRNA Knock down of Astrocytes Affects Glutamate Metabolism Leading to Extensive Accumulation of the Neuroactive Amino Acids Glutamate and Aspartate”. Neurochemical International (2012). https://pubmed.ncbi.nlm.nih.gov/26221781/
A. A. Akopian, H. Hertz, and J. W. Phillips. “Expression of the Human Isoform of Glutamate Dehydrogenase, hGDH2, Augments TCA Cycle Capacity and Oxidative Metabolism of Glutamate During Glucose Deprivation in Astrocytes”. Glia (2017). https://onlinelibrary.wiley.com/doi/abs/10.1002/glia.23105
Lactic acid (lactate) is the direct product of the reaction catalyzed by lactate dehydrogenase (LDH). High lactate levels directly correlate with increased LDH activity.
Lee, J., Kim, J., Lee, S., & Kim, J.. Association between serum lactate dehydrogenase and frailty among individuals with metabolic syndrome. PLOS ONE (2021). https://doi.org/10.1371/journal.pone.0257473
