[Annual cycle of the changes in the mitotic activity of gastric mucosal epithelium in hibernating rodents].

It was shown that mitotic activity of the gastric mucosa epithelium in Citelius erythrogenus Br. is characterized by pronounced seasonal changes. The highest mitotic index was recorded 3-4 days after the arousal from hibernation, while the lowest one during summer time (May-June). The mitoses are blocked during winter torpor. The circadian peak of the mitotic activity in summer was recorded at 10 p.m. The mitotic cells were discovered not only in the generative zone but also at all the levels of the fundal and pyloric glands. Radioautography with 3H-thymidine administration in vivo is not fit for studying the synthesis of DNA in sousliks.