The cell proliferation kinetics of psoriasis examined by three in vivo techniques.

The cell proliferation kinetics of the germinative compartment in psoriasis have been re-investigated with tritiated thymidine and vincristine techniques. The mean cell cycle durations calculated from an extended fraction of labelled mitoses experiment were Tc=56 h, t1=43 h, ts=7-7 h and t2=5-6 h. Combination of the results of the FLM experiment with the experimental labelling index and the experimental birth rate suggests a growth fraction of unity and an exponential age distribution for the germinative population. An exponential age distribution is supported by the presence of several layers of germinative cells and the direction of the mitotic axes during cell division.