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 acrylamidegel electrophoresis of leukocyte extracts. Normal lymphocytes showed a hightotal H-LDH (heart type) activity (67 per cent) with 25 per cent in LDH-1and only 3.5 per cent in LDH-5. Lymphocytes from chronic lymphatic leukemia(CLL) and lymphosarcoma leukemia (LSA-LL) had less LDH-1, and moreLDH-3 and LDH-4, than normal lymphocytes. The H-LDH fell to 60.5 per centin 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. Inmyelogenous leukemia, myeloblasts had the most LDH-1 and H-LDH, whilemature PMN had the least. PMN leukocytes isolated from CLL, LSA-LL, andmyelogenous leukemia had LDH patterns like the normal. Monocytes fromacute monocytic leukemia were low in LDH-1 and LDH-5, but had a high totalenzyme content. They evidently were rich in LDH-2, 3, and 4.

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

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

Submitted on May 5, 1966 Accepted on June 26, 1966