Seasonal variations of DNA synthesis in intestinal epithelial cells of hibernating animals--I. DNA synthesis in intestinal epithelial cells of ground squirrel (Citellus undulatus) during deep hibernation.

The conditions for obtaining crypt cells from ground squirrel small intestine were chosen which allow flow-through cytofluorometric analysis of the DNA synthesis of this tissue. DNA synthesis was found to be greatly reduced in the intestinal crypt cells of ground squirrel during deep hibernation in torpid animals, in animals during spontaneous arousals and in animals prevented from hibernation. The conclusion is made about endogenous control of the DNA synthesis in the cells of true hibernators.