ROLE OF ADRENAL MEDULLA IN MORPHINE‐INDUCED HYPERTHERMIA THROUGH CENTRAL ACTION

Abstract

The role of the adrenal glands, in morphine‐induced hyperthermia was studied in normal, chemically‐sympathectomized, adrenalectomized, adrenal‐demedullated or splanchnicotomized rats. In restrained female rats, 5 mg/kg morphine produced hyperthermia whereas 20 mg/kg and 40 mg/kg produced hypothermia. After adrenalectomy, 5 mg/kg morphine did not produce hyperthermia. After adrenal‐demedullation or adrenal‐denervation (splanchnicotomy), 5 mg/kg morphine did not produce hyperthermia. The results suggest that, in the rat, the adrenal medulla plays an important role in morphine‐induced hyperthemia, and that morphine acts centrally to stimulate the medulla. 1982 British Pharmacological Society