ADRENOCORTICAL RESERVE IN HYPERTHYROIDISM

Abstract

The responses of urinary 17-hydroxycorticosteroids (17-OH-CS) to two stimulation methods with repository ACTH were investigated in patients with hyperthyroidism.
Baseline values for total urinary 17-OH-CS were significantly elevated in hyperthyroidism. The study on the diurnal variations in total urinary 17-OH-CS revealed the greater magnitude of variation in hyperthyroidism than in the normal group.
The urinary 17-OH-CS response to 30 I. U. of ACTH-Z injected every 12 hrs. for 5 days increased more quickly and to much higher levels in hyperthyroidism than in normal subjects, whereas the response to 30 I. U. of ACTH-Z injected only every 24 hrs. for 5 days showed no further rise or much slower rise after the 2nd or 3rd day of the stimulation. The effects of a single injection of 30 I. U. of ACTH-Z had a tendency to decline more rapidly in hyperthyroidism than in euthyroid subjects.
These results appear to indicate that in hyperthyroidism 1) there is no sign of impairment of adrenocortical reserve, at least under the continuous maximum stimulation of the adrenal cortex for 5 days, 2) the capacity of the adrenal cortex in the ability to secrete corticosteroids is greater than in normal subjects and 3) the effects of ACTH disappear more rapidly than in normal subjects.