[Diurnal variations in the duration of mitosis in the mouse esophageal epithelium]

Considerable differences were found in the morning and the evening mitotic indices of the epithelium in the oesophagus of C57BL/6J mice. By the colchamin method it was shown that the duration of mitosis was the same in the morning and the evening hours and was equal to 34--49 minutes. The results varied and depended on the dose of colchamin and duration of its action. Thus, the diurnal differences in mitotic index of the epithelium in the oesophagus depended on the differences in mitotic activity, the number of mitoses per time unit. It is emphasized that colchamin method should be used with great caution to obtain reliable results.