[Analysis of changes in mitotic activity and epidermal G2 chalone content in esophageal and tongue epithelia during the course of the day].

The epidermal G2-chalone level and mitotic activity variations in the epithelium of the rabbit esophagus and tongue and correlation of these indices were studied during the day. Mitotic activity was determined by the mitotic index calculation. The epidermal G2-chalone localization was determined by the Coons indirect method with monospecific immune serum. Circadian rhythms of the mitotic activity with maximal level at morning hours and circadian rhythms of chalone synthesis were discovered in the epithelium of both the organs. The decrease of G2-chalone concentration was followed by maximal mitosis in the epithelium under consideration. Obviously, the increase of the mitotic activity was caused by the decrease of G2-chalone concentration. An assumption about circadian rhythms of mitosis formation by means of G2-chalones has been confirmed by the data obtained.