Effect of corticosteroid therapy of different duration on urinary elimination of norepinephrine

Abstract

Corticosteroid hormones administered into the organism for therapeutic purposes have a certain effect on different organs and systems, especially on the endocrine system. It was interesting to find out the effect of corticosteroid therapy of different duration on the sympathetic adrenal system i.e. on urinary elimination of norepinephrine. The examination concerned 28 patients with systemic diseases and 8 healthy individuals who never were given corticosteroids. The patients were divided into 3 groups: 1). group on a short therapy; 2). group on a long therapy and 3). group on a prolonged therapy. The amount of norepinephrine in urine was determined by spectrophotofluorometric method. A multiphasic urinary elimination of norepinephrine was registered. After a short therapy corticosteroids provoked a decreased norepinephrine elimination i.e. a decreased activity of the sympathetic nervous system. After a several-month-therapy the elimination of norepinephrine returned to normal. However, after a prolonged corticosteroid therapy a definite decrease of sympathetic activity was observed. The result showed a positive correlation between norepinephrine excretion and administered dose of Pronison. The greatest fall of sympathetic activity was observed during small, suppressive doses of Pronison (5 mg daily). A prolonged administration of 80 mg doses increased urinary elimination of norepinephrine. This is possibly due to a central stimulating activity of corticosteroids on the sympathicus. It is concluded that a prolonged corticosteroid therapy provoked a fluctuation of sympathetic activity. Therefore the therapy should be intermittent. It is known that a prolonged corticosteroid treatment, especially a synthetic corticosteroid therapy, can provoke hypertension which is the consequence not only of water and salt retention, but also of increased sympathetic activity.