DIURNAL URINARY CORTICOID EXCRETION IN THE HUMAN AND GORILLA

Urinary corticoids were measured in humans (n = 9) in frequently colle cted urine samples taken during a 48 hr period, and in captive western lowland gorillas (n = 5) and free-ranging mountain gorillas (n = 3) f rom samples taken from 0700 to 1800 hr. In each study, the highest con centrations occurred in the morning hours, then declined gradually, re aching the lowest levels in the afternoon to evening. These data show that a similar diurnal pattern of corticoid excretion does occur in th ese species. We suggest that if single-sample urine collection for det ermination of hyperadrenal activity is to be used, urine is best colle cted during hours of low corticoid excretion. (C) 1994 Wiley-Liss, Inc .