Malic and Lactic Dehydrogenase Isozymes of Normal and Leukemic Leukocytes Separated on Glass Bead Columns

Five LDH and two MDH isozyme bands were obtained with acrylamide gel electrophoresis of leukocyte extracts. Normal lymphocytes showed a high total H-LDH (heart type) activity (67 per cent) with 25 per cent in LDH-1 and only 3.5 per cent in LDH-5. Lymphocytes from chronic lymphatic leukemia (CLL) and lymphosarcoma leukemia (LSA-LL) had less LDH-1, and more LDH-3 and LDH-4, than normal lymphocytes. The H-LDH fell to 60.5 per cent in CLL and 56 per cent in LSA-LL. PMN leukocytes had low H-LDH activity (38.8 per cent) with 3.3 per cent in LDH-1 and 25.8 per cent in LDH-5. In myelogenous leukemia, myeloblasts had the most LDH-1 and H-LDH, while mature PMN had the least. PMN leukocytes isolated from CLL, LSA-LL, and myelogenous leukemia had LDH patterns like the normal. Monocytes from acute monocytic leukemia were low in LDH-1 and LDH-5, but had a high total enzyme content. They evidently were rich in LDH-2, 3, and 4.

Lymphocytes had less MDH-1 (60 per cent) than PMN leukocytes (78 per cent). In CLL, lymphocyte MDH-2 increased. In myelogenous leukemia, myeloblasts had the most MDH-2 and mature PMN the least. Monocytes from monocytic leukemia contained a little more MDH-2 than PMN leukocytes.

In general, white cell immaturity and/or ability to divide was associated with high levels of LDH-1, total H-LDH, and MDH-2.