Formation of Alcohol Motivation in Monkeys (Macaca mulatta) Kept in Isolation.

The effects of environmental factors (flavors, different ethanol concentration, alcoholic deprivation, and food reinforcement) on the formation of alcohol motivation was studied in rhesus macaques (Macaca mulatta, n=6). Motivation for alcohol intake was induced in two stages: initiation (sessions 1-160) and formation of motivation (sessions 161-516). Monkeys preferred multifruit flavor and 4% ethanol solution, while ethanol deprivation did not stimulate alcohol consumption.

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.

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

Background: The objective of this study was to evaluate the role of the adrenal cortex in the regulation of antioxidant enzyme defense and to characterize this regulation in different age periods.

Methods: Five young and five old female rhesus monkeys were subjected to 2 hours squeeze cage restraint stress at 0900 or 1500 hours. Plasma levels of corticosteroids and activities of erythrocyte antioxidant enzymes were measured before the stress and 30, 60, 120, 240 minutes after beginning of the stress.

Correlation between activity of antioxidant enzymes and circadian rhythms of corticosteroids in Macaca mulatta monkeys of different age.

Young rhesus monkey females (Macaca mulatta) demonstrate the well-defined circadian rhythm in activity of erythrocyte SOD with maximum at 10.00 h and minimum at 22.00 h.