[Changes in the mitotic activity and destruction of rat thymus lymphocytes following hydrocortisone administration at different hours of the day].

The 24-hour rhythm of mitoses was identical in the thymus lymphocytes of 30-day rats in control and in experimental animals 4 hours after injection of hydrocortisone. In the control rats the number of degenerating lymphocytes failed to alter in the course of 24 hours. Four hours after the hydrocortisone injection of degenerated cells increased sharply; however, the rate of the lymphocyte destruction was more significant at night and early in the morning than during the day and the evening.