CHO cell enlargement oscillates with a temperature-compensated period of 24 min

The rate of increase in cell area of CHO cells when measured at intervals o f I min using a light microscope equipped with a video measurement system, oscillated with a minimum period of about 24 min. The pattern of oscillatio ns paralleled those of the 24 min period observed with the oxidation of NAD H by an external cell surface or plasma membrane NADH oxidase, The increase in cell area was non-linear. Intervals of rapid increase in area alternate d with intervals of rapid decrease in area. The length of the 24 min period was temperature-compensated (approximately the same when measured at 14 de greesC, 24 degreesC or 34 degreesC) while the rate of cell enlargement incr eased with temperature over this same range of temperatures. (C) 2000 Elsev ier Science B.V. All rights reserved.