[Circadian rhythm of corticosteroids in female hamadryas baboons during long-term hypokinesia].

Radioimmunoassay was used to study the effect of restricted motor activity on the circadian rhythms of the content of hydrocortisone, 11-deoxycortisol, corticosterone and aldosterone in the blood plasma of mature female hamadryas baboons in different phases of the menstrual cycle. Intact animals demonstrated distinct circadian rhythms of corticosteroids reproduced stably in both phases of the cycle. Two-week immobilization did not change the general nature of rhythms of the content of glucocorticoids but caused a decrease in their mean daily concentrations which is significant for 11-deoxycortisol and corticosterone of female baboons immobilized in the luteal phase of the cycle. The circadian rhythm of aldosterone got smooth, its level in the blood dropped significantly disregarding a cycle phase at the moment of immobilization. The revealed changes of the circadian rhythms of aldosterone reflect disorders of adrenocortical mineralocorticoid function in female baboons under hypokinesia. Causes of changes in the hormonal activity of the adrenal cortex under clinicostatic hypokinesia are discussed.