Age-specific and individual features of vasopressinergic regulation of the hypothalamic-pituitary-adrenal system in primates.

Experimental study was carried out on young mature (6-8 years) and old (21-27 years) rhesus macaques with anxious and depression-like behavior and with standard (control) adaptive behavior. The responce of the adenohypophysis to arginine vasopressin depended on age and the type of adaptive behavior. Young animals with standard behavior demonstrated much higher concentrations of ACTH in the peripheral plasma in response to arginine vasopressin than old animals.

Aging of the hypothalamic-pituitary-adrenal axis in nonhuman primates with depression-like and aggressive behavior.

We have investigated aging of the hypothalamic-pituitary-adrenal (HPA) axis in female rhesus monkeys that differ in adaptive behavior. Plasma cortisol (F) and dehydroepiandrosterone sulfate (DHEA-S) concentrations under basal conditions and under acute psycho-emotional stress were evaluated in blood plasma of young (6-8 years) and old (20-27 years) female rhesus monkeys with various types of adaptive behavior (aggressive, depression-like, and average). We have found that the age-related changes in the HPA axis of monkeys with depression-like behavior were accompanied by the maximal absolute and relative hypercortisolemia under both basal conditions and stress.

[Age-related changes of the hypothalamic-pituitary-adrenal axis in individuals with various types of adaptive behaviour].

The purpose was to study age-related changes of the hypothalamic-pituitary-adrenal (HPA) axis function and their interrelations with features of cognitive aging in individuals with various type of adaptive behaviour on model of laboratory primates. Plasma cortisol (F) and dehydroepiandrosterone sulfate (DHEAS) levels in basal conditions (0900h and 2100h of day) and under acute psycho emotional stress (2-hour moderate restraint) were estimated in blood plasma of 34 young (6-8 years) and 34 old (20-27 years) female rhesus monkeys with various types of adaptive behaviour (aggressive, adequate, depressive-like). We have found that the age-related changes in HPA of monkeys of the depression-like behavior were accompanied by the maximal absolute and relative hypercortisolemia in the basal conditions as well as in the stress conditions.

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

Activity of glutathione-dependent antioxidant enzymes (glutathione peroxidase, glutathione reductase, and glutathione transferase) in blood erythrocytes from female Macaca mulatta (6-8 and 20-26 years) was measured during activation of the hypothalamic-pituitary-adrenal system under conditions of acute psychoemotional stress (2-h restraint stress). Glutathione reductase activity increased during stress, depended on the time of day, and strongly correlated with blood corticosteroid level. Circadian variations in stress reactivity of glutathione reductase during aging were accompanied by similar changes in stress reactivity of the hypothalamic-pituitary-adrenal system.

Stress, aging and reliability of antioxidant enzyme defense.

Clinical and experimental data point to existence of disturbances of adaptive ability of aged organism to extreme impacts. However mechanisms of these disturbances are not clear yet. The purpose of the investigation was to study age-related changes in reaction of erythrocyte antioxidant enzyme system in response to acute psycho-emotional stress and a possible role of these changes in age-related alterations of oxygen blood transport in nonhuman primates.