Corticosteroids and
ascorbic acid in the adrenal glands of adult cats have been investigated after single or repeated administration of
morphine. Also plasma levels and urinary excretion of
corticosteroids were determined. A significant increase in the content of
corticosteroids in the glands and plasma was found after initial injection of
morphine. After 7 days of consecutive
morphine treatment a fall of
corticosteroids in the glands was observed; after 2 weeks of daily
injections the content of adrenal
corticosteroids was significantly lower than in the control animals but no change was found in the plasma. Administration of the
drug during 1 month led to a highly significant decrease of
corticosteroids in the glands as well as in plasma. No significant change in adrenal ascorbic
acids was found whether the adrenal
corticosteroids were higher or lower than in the control cats. Urinary
corticosteroids were high during the first week of
morphine treatment but thereafter the excretion declined progressively and was lower than the control level after 13 days of treatment. The significant decrease of
corticosteroids observed after repeated administration of
morphine and the rise in adrenal
corticosteroids found after the injection of
nalorphine to the morphinized animals suggest that some kind of
morphine dependence had been developed in the cats after repeated administration of the
drug.