Effect of Low-Dose Cortisol Therapy on Epinephrine Excretion in Man

ABSTRACT

Eight patients with rheumatoid arthritis were studied before and after 3 months of treatment with 20 mg of cortisol per day. A significant decrease in the urinary excretions of epinephrine and catecholamines in response to insulin hypoglycemia was seen after therapy. Adrenal cortical function was suppressed by the exogenous cortisol as measured by 8:00 AM plasma cortisol and by cortisol response to hypoglycemia. These data support the concept that in man, as in animals, full activity of phenylethanolamine N methyl transferase requires high levels of corticosteroids bathing the adrenal medulla. Suppression of endogenous corticosteroid production decreases the activity of this epinephrine forming enzyme and thereby results in a decrease in epinephrine production and excretion.