[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.

[Peptide correction of age-related pineal disturbances in monkeys]. / Peptidnaia korrektsiia vozrastnykh narushenii funktsii épifiza u obez'ian.

Investigation of the age-related changes of the pineal gland function and possible ways for their overcoming on nonhuman monkey model was the purpose of this study. Hormonal function of the pineal gland was studied in 38 Macaca mulatta females of two age groups: 6-8 years old, n = 18 and 20-26 years old, n = 20. Pineal function was studied in basal conditions and after administration of pineal peptide preparations--epithalamin and epitalon, both developed in the St. Petersburg Institute of Bioregulation and Gerontology (Russia). It has been revealed that plasma melatonin concentration in monkeys has well expressed high amplitude diurnal rhythm. Minimum is manifested at 4 p.m. and maximum--at 10 p.m.-3 a.m. In aging the mean diurnal melatonin concentration decreases by 1.5-2 times as well as in different points of the day: 9 p.m., 10 p.m., 3 a.m. and 4 a.m. Administration of pineal peptides--epithalamin (at the dose 5 mg/animal/day intramuscularly during 10 consecutive days) or epitalon (at the dose 10 micrograms/animal/day intramuscularly during 7-10 consecutive days) induced significant increase in the night plasma melatonin in old monkeys, but the treatment did not change the melatonin level in young monkeys. Taking into consideration that melatonin is very important for regulation of the diurnal rhythm of functioning of some organs and systems it should be suggested that applying epithalamin and epitalon are perspective in the correction of age-related hormonal imbalance and age pathology.