DISTINCT, VERY HIGH-FREQUENCY OSCILLATIONS IN THE ACTIVITY AND AMOUNTOF ACTIVE ISOZYME OF LACTATE-DEHYDROGENASE IN MURINE ERYTHROLEUKEMIC CELLS AND A CELL-FREE SYSTEM

Electrophoretic and kinetic determinations of the activity of lactate dehydrogenase in murine erythroleukaemic (MEL) cells, sampled at 1 min intervals, reveal distinct oscillations in the activity and amount of active isozyme. Both oscillations have periods in the range of 2-6 mi n (probably less) and both appear to be rhythmically modulated with re spect to period, amplitude and mean. The oscillations also occur in ce ll-free systems, a fact which throws doubt on the value of studies whe re it is assumed that such preparations have constant composition. (C) 1996 Academic Press Limited