lactic acid dehydrogenase
Meaning of lactic acid dehydrogenase: Lactic acid dehydrogenase is an enzyme found throughout body tissue, and a rising blood level points to cell damage from many causes, not only cancer.
Definition of lactic acid dehydrogenase
Lactic acid dehydrogenase, commonly abbreviated LDH, is an enzyme that helps convert lactate to pyruvate and back again as part of the cellular pathway that produces energy without oxygen. It is present in nearly every tissue in the body, including the heart, liver, kidney, skeletal muscle, lung, and red blood cells.
Because the enzyme is so widespread, an elevated level in the blood is not specific to any single organ or disease. It commonly rises with tissue injury from a heart attack, muscle damage, liver disease, infection, or the breakdown of red blood cells, and some cancers also raise it as tumor cells turn over rapidly.
The enzyme exists as several isoenzymes built from different combinations of protein subunits, and these forms are distributed unevenly across organs, so laboratories sometimes examine the isoenzyme pattern rather than the total level alone to help narrow down which tissue is affected.
Also known as
Used in a sentence
Serum lactic acid dehydrogenase was measured as part of the laboratory workup for the patient's fatigue and jaundice.
Good to know
A high lactic acid dehydrogenase level is a nonspecific sign of tissue turnover or damage and is generally interpreted together with other tests rather than as evidence of a particular disease on its own.
Word origin
Where “lactic acid dehydrogenase” comes from
Formed from Latin lac, lactis, meaning milk, the root of lactate, combined with dehydrogenase, from de-, meaning removal, and hydrogen, with the enzyme suffix -ase, meaning an enzyme that removes hydrogen atoms during a reaction.