Lactate Dehydrogenase Isoenzyme Electrophoretic Pattern in Serum and Tissues of Mammalian and Bird Origin

Lactate dehydrogenase (LDH) is a tetrameric enzyme that in vertebrates exists in five electrophoretically distinguishable forms known as isoenzymes. According to their different mobility to anode, they are denoted LDH 1 (H 4 ), LDH 2 (H 3 M), LDH 3 (H 2 M 2 ), LDH 4 (HM 3 ), and LDH 5 (M 4 ). A buffer system of the pH values 8.6–8.8 is commonly used for the separation of these isoenzymes in mammals. In the case of bird LDHs, the observation of five fractions is very difficult under this condition as they usually produce a pattern of one diffuse zone. Isoelectric focusing technique (IEF) in the pH range of 3–9 enabled a good and clear resolution of all five bird LDHs. Using this technique, it was also possible to observe the pattern in some tissues of chicken embryo. pattern where anodic LDH 1 -LDH 3 dominate over cathodic form/s. Mammalian tissues pattern of lactate dehydrogenase isoenzymes differs from species to species with the highest enzyme activity in the skeletal muscle followed by heart and liver. Chicken adult and embryonic lac tate dehydrogenases differ each other especially in the pattern of breast muscle with all five isoenzymes being present in the tissue of embryonic origin.