Abstract
The incubation of normal peripheral blood lymphocytes with phytohaemagglutinin results in an increase in DNA synthesis accompanied by an increase in ferritin synthesis, as determined by 3H-leucine incorporation into ferritin isolated by immunoprecipitation. The increase was 5 to 8 times greater than that of non-stimulated cells. This phenomenon was associated with a 3- to 6-fold increase of intracellular ferritin when compared with the original ferritin concentration. While the significance of increased ferritin expression in proliferative cells is not known, an increase in ferritin synthesis following in vitro stimulation is probably related to increased metabolic activity of the cells.