INDEPENDENT HIGH-FREQUENCY OSCILLATIONS IN THE AMOUNTS OF INDIVIDUAL ISOZYMES OF LACTATE-DEHYDROGENASE IN HL60 CELLS

Early studies, using kinetic methods, suggested that the isozyme patte rn of lactate dehydrogenase in various cells oscillated with time. Mor e recent electrophoretic studies on murine erythroleukaemic cells (whi ch exhibit only one isozyme) indicated very high frequency variations (period 2 min or less) in the amount of the lone active isozyme. We no w show that in HL60 cells, the activity stain intensities of the two m ajor isozyme bands both oscillate but the temporal variations are dist inct. As with other cellular rhythms, each of the two periodicities se em to be modulated in cyclic fashion with respect to period, amplitude and mean levels, the periods of both the primary and modulating rhyth ms being of the order of 10-15 min or probably much less. (C) 1996 Aca demic Press Limited