[Stress, aging, hypothalamic-pituitary-adrenal axis and reliability of antioxidant enzyme defence]

The purpose of the investigation was to study age-related changes in reaction of the hypothalamic-pituitary-adrenal axis and erythrocyte antioxidant enzyme system in response to acute psychoemotional stress in non human primates. Ten young (6-8 years) and ten old (20-26 years) healthy female rhesus monkeys were subjected to acute moderate psycho-emotional stress (two hours squeeze cage restraint) at 15:00 h. Plasma cortisol (F), activities of superoxide dismutase (SOD), glutathione peroxidase, gluthatione reductase (GR), gluthatione-S-transferase, and lipid peroxidation products (TBARS) in erythrocytes were measured before stress and 30, 60, 120, 240 min and 24 h after beginning of the stress. In young monkeys SOD activity decreased in response to the stress while it increased in the half of old monkeys. Young animals also demonstrated essentially higher increase in plasma F level and GR activity in response to the restraint, in comparison with old monkeys. Level of TBARS did not change in response to the stress in young animals and significantly increased in old monkeys. The age-related alterations in F, SOD, and GR stress responsiveness lead to activation of peroxide oxidation of lipids that may be considered as an important factor of aging damage of erythrocyte functioning and reliability of oxygen transport to tissues under stress conditions.