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Lactate dehydrogenase isoenzyme 1 in blood
Medical expert of the article
Last reviewed: 05.07.2025
Reference values (norm) of lactate dehydrogenase 1 activity are 15-25% of the total lactate dehydrogenase activity in the blood serum.
Lactate dehydrogenase isoenzymes are contained in tissues in a strictly defined ratio, i.e. each tissue, including blood, has a characteristic, unique to it, spectrum of lactate dehydrogenase isoenzymes. In a number of pathological conditions, when the permeability of cell membranes increases in one or another organ and tissue damage occurs, lactate dehydrogenase isoenzymes enter the blood in excess. Since the activity of isoenzymes in tissues is several hundred times higher than their activity in blood serum, the spectrum of lactate dehydrogenase isoenzymes in it becomes similar to the spectrum of lactate dehydrogenase isoenzymes in the affected organ. Normally, the ratio of lactate dehydrogenase isoenzyme activity in blood serum is as follows: LDH 1 - 15-25% of total activity, LDH 2 - 30-40%, LDH 3 - 20-25%, LDH 4 - 10-15%, LDH 5 - 5-15%.
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