[Cell population kinetics in the mouse epidermis stimulated by plucking the hair]

Indices of mitotically dividing and DNA-synthesizing cells, the curve of labeled mitoses, and the continuous 3H-thymidine labeling were used for analysing the kinetics of epidermis cell populations in mice C57Bl after plucking. Within the initial 15 hours following stimulation, only one cell population was seen to start proliferating. This passed through the period of transformation (6 hours) and G1-period (3 hours) to enter into S-phase 9 hours after plucking. At this time, the increase in the mitotic level occurs, being at the expense of part of the cells leaving R2-phase. 20 hours after the operation, the cycle of the first population is over, in part of these cells, after having left S-phase, remain in R2-phase. At the same time, epidermocytes of another population are seen to commence their entry into S-phase. Determined from the curve of labeled mitoses, the duration of the whole cycle of epidermocytes, and of G1, S, and G2+M phases appeared to be 12, 3, 6 and 3 hours, respectively.