Evidence suggesting 11 β-hydroxylase inhibition during aminoglutethimide administration

Steroid hormone excretion during amino-glutethimide administration was studied in a patient with Cushing's syndrome due to bilateral adrenocortical hyperplasia. Plasma and urinary 17-OHCS showed a persistent decrease, as did urinary total 17-KS. Chromatographic fractionation of urinary 17-KS demonstrated a dramatic reduction of 11-oxy-17-KS, while 11-deoxy-17-KS, after a transient fall, tended to recover. Urinary THS showed an absolute increase, while pregnanetriolone diminished. Δ⁵-pregnenetriol and pregnanetriol, after initial decreases, showed a gradual trend upward. The sum of these data, and particularly the increase in THS excretion, suggests that, in this case, aminoglutethimide exerted an inhibitory effect not only on the early steps of adrenocortical steroidogenesis but also on 11 β-hydroxylation.