The role of vasopressin suppression in phencyclidine-induced diuresis

Phencyclidine (PCP; 10 mg/kg, s.c.) produced a marked diuresis which occurred without significant changes in solute excretion. This diuresis occurred predominantly within 2 h of PCP injection, and was blocked by pretreatment with vasopressin. The maximum diuresis corresponded temporally to a significant fall in plasma vasopressin and rise in mean arterial pressure. Thus, PCP-induced diuresis is due, at least in part, to suppression of plasma vasopressin. This suppression is probably related to the rise in blood pressure, though direct effects of PCP on the neurohypophysis cannot be excluded.