[Proliferative activity of experimental brain tumors]

The method of autoradiography was used to study the parameters of the cell cycle and the intensity of proliferative processes in three transplantable rat brain tumors differing in the duration of the latent period and sensitivity to chemotherapy. The tumors were found to be similar in the duration of the cell cycle and its phases, the mean values of the label index and growth fraction, and were characterized by the irregularity of the proliferative processes within the tumor; the label index was higher in the center of the tumors (threefold in one case) than in the zone of their growth. It is suggested that the sensitivity of brain tumors to chemotherapy does not depend on their cell kinetics.