Influence of Some Environmental Factors on Plasma and Urinary 17-Hydroxycorticosteroid Levels in the Rhesus Monkey

Abstract
Observations in the rhesus monkey are described suggesting a close relationship between emotional responses to environmental factors and pituitary-adrenal cortical activity, as judged by plasma and urinary 17-OH-CS levels. Substantial elevations of plasma 17-OH-CS levels occurred in a group of normal monkeys following their first experience with a handling and venipuncture procedure. This effect did not occur in subsequent experiments of the same type. Animals placed in a chair restraining apparatus for the first time showed a moderate rise in urinary and plasma 17-OH-CS levels during the first few days but thereafter stabilized at low levels for at least 3 weeks. It is concluded that the chair technique is, therefore, suitable for studies of ACTH regulation and perhaps many types of biological studies. Urinary 17-OH-CS levels were approximately 30% lower on weekends than weekdays in monkeys kept in a laboratory room, presumably reflecting the influence of the animal's interaction with the everyday environment on the pituitary-adrenal cortical system.