[Hydroxyurea synchronization of cellular proliferation in the esophageal epithelium of mice with tumors].

The synchronizing effect of hydroxyurea on the passage of the esophagus epithelia cells through the stage of the DNA synthesis and mitosis was investigated in albino mice bearing sarcoma. Dinrnal variations in the number of epithelial cells at these stages of the mitotic cycle were taken into consideration. Two mutually complementary indices for the measurement of the shifts in the cell population and the rate of the synchronization are used. Two cell groups which passed the S-phase and mitosis synchronously were found in artificial synchronization in the esophageal epithelium. The synchronization indices characterizing the first group were lower than control. In the second group the cell count during the DNA synthesis was double as compared with the number of cells synthesizing DNA in natural synchronization; however, the rate of the changes in the synchronism was the same in the experimental and control groups.