[Evaluation of the size of the proliferative pool and the length of the mitotic cycle according to the accumulation curve of labelled cells].

Abnormal increase of the accumulation curve of H3-thymidine labelled cells for the systems with proliferative pool Pc less than 1 (rat mesothelium and the basal cells of the epithelium of the hamster cheek pouch) is due to stimulation of cell transition from R1 phase to the regulatory G1r phase (the dichophase) within G1 period of the mitotic cycle. The stimulation was assumed to depend on the radiation and transmutation defects in DNA due to H3 disintegration, and to occur when the stream of labelled cells reached the G1r phase. Proliferative pool and the duration of mitotic cycle can be estimated by means of coordinates of the abnormal curve.