This test measures the relative percentage of isoenzymes (LD1-5).
Lactate dehydrogenase (LD) is an enzyme that is found in almost all of the body's cells, but only a small amount of it is usually detectable in the blood. LD is released from the cells into the bloodstream when cells are damaged or destroyed. Because of this, the LD test can be used as a general marker of injury to cells.
Although there is some overlap, each of the five LD isoenzymes tends to be concentrated in specific body tissues. In general, the isoenzyme locations are as follows:
LD-1: heart, red cells, kidney
LD-2: heart, red blood cells, kidney (lesser amounts than LD-1)
LD-3: lungs and other tissues
LD-4: white blood cells, lymph nodes, muscle, liver (lesser amounts than LD-5)
LD-5: liver, skeletal muscle
Fasting is not required for this test. Take all medications as prescribed.