[Influence of spontaneous arousal during hibernation of the activity of the pituitary-adrenal system in the suslik Citellus erythrogenis].

Periodic spontaneous arousals of ground squirrels during hibernation are accompanied by activation of the hypophyseal-adrenal system. However, together with a 3-fold increase in hypophyseal ACTH and 2-fold increase in 11-oxycorticosterioid secretion by the adrenals, more than 2-fold decrease in the content of these hormones in the peripheral blood was observed. The latter may result from the increased corticosteroid metabolism. It is suggested that spontaneous arousals may act as a synchronizer of endogenous rhythm of the activity of the hypophyseal-adrenal system during winter hibernation.