Effect of aging on stress reactivity of the adrenal cortex in laboratory primates. Dependence on the time of day

Abstract

Age-specific differences in the reaction of the hypothalamic-pituitary-adrenal system to acute psychoemotional stress (immobilization) was studied in female rhesus macaques aged 6-8 and 20-27 years at different time of the day. The reactivity of the hypothalamic-pituitary-adrenal system during immobilization at 15.00 was lower in old animals, while at 9.00 there were no age-specific differences or the reactivity was higher in old animals.

Hypothalamic-pituitary-adrenal system and enzymes of the glutathione-dependent antioxidant system during stress and aging

“…DHEA-S concentration in these monkeys tended to increase more significantly after stress at 15.00 (Table 2). Similar results were obtained previously with young female rhesus monkeys [2]. These data illustrate the existence of circadian variations in stress reactivity of HPAS.…”

“…These data illustrate the existence of circadian variations in stress reactivity of HPAS. Circadian variations in stress reactivity of the adrenal cortex are probably related to greater stress reactivity of adrenocorticotropic hormone at 15.00 [2].…”

Circadian and age‐related changes in stress responsiveness of the adrenal cortex and erythrocyte antioxidant enzymes in female rhesus monkeys

“…In response to stress, the increase of blood corticosteroid concentration in the afternoon was either significantly higher (F) or tended toward higher values (DHEAS) compared with the increases in concentrations seen in the morning (0900 hours); These differences were observed regardless of whether the values were measured in absolute or relative units ( Table 1). The underlying cause of a circadian rhythm in stress responsiveness of the adrenal cortex is likely due to the previously reported higher stress responsiveness of ACTH in the morning compared to the afternoon [8,11].…”

Stress Responsiveness of the Hypothalamic–Pituitary–Adrenal Axis: Age-Related Features of the Vasopressinergic Regulation

“…Recent experiments on non-human primates (Goncharova, 2006, 2009a; Goncharova et al, 2006a, 2008b), had shown that stress responsiveness of the HPA axis depends to a large extent on the time of day when stimulus is applied as well as on initial sensitivity of the HPA axis. It was shown that the circadian rhythm of ACTH and cortisol level is evident not only in basal conditions but also in response to acute psycho-emotional stress.…”

“…This leads to higher average levels of glucocorticoids during the day in humans and most other primates and to higher activity of the HPA axis during the night in rodents (Goncharova et al, 2002; Kalsbeek et al, 2010; Russell et al, 2010; Walker et al, 2010). Stress responsiveness of the pituitary–adrenal axis in humans and non-human primates also shows the circadian rhythms with higher stress response in the afternoon and evening, and lower in the morning (Goncharova, 2006; Goncharova et al, 2006a; De Weerth et al, 2007). Rhythmicity in the HPA axis is essential for the normal functioning of the brain and other glucocorticoid responsive organs (Van Cauter et al, 1997; Lupien et al, 2002; Yoshimura et al, 2007; Goncharova et al, 2008a,b).…”