Lactic dehydrogenase of human chronic lymphocytic leukemic leukocytes.

flECENT INVESTIGATIONS by Markert and Moeller1 and Wieland and 1 Pfieiderer2 have shown by electrophoresis that lactic dehydrogenase ( LDH ) occurs in multiple molecular forms, with certain molecular species of the enzyme being present in greater amount in certain tissues. The electrophoretic form which we call isozyme I ( see fig. 1 ) predominates in extracts of heart muscle while the isozyme V predominates in extracts of liver and skeletal muscle. The present study was established to characterize the lactic dehydrogenase present in chronic lymphocytic leukemic cells and to determine if the enzyme differed quantitatively or qualitatively from the LDH of nonleukemic leukocytes.