[The action of antimitotics and the cell cycle].

Cell kinetics, which for a long time could only be worked out at the level of mitosis, has now at its disposal a set of technics which make it possible to label cells which replicate their DNA, to appraise the DNA content of individual cells and to synchronise cell populations. First of all, the meaning and the scope of results obtained by cell kinetics technics in the study of the action mechanism of antimitotic substances are discussed. The main results obtained are exposed, pointing to the complexity of the mechanisms concerned. A more detailed discussion of some personal results concerning the action of anti-inflammatory substances, of protein inhibitors and of hydroyure allows to underline the difficulties met with and the importance of the choice of an adequate methodology.