THE INFLUENCE OF 17α-METHYL-19-NORTESTOSTERONE (M. N. T.) ON THE METABOLISM OF CORTISOL

Abstract

ABSTRACT The effect of prolonged 17α-methyl-nortestosterone (M. N. T.) administration on cortisol metabolism was studied in several patients. 1. A decreased urinary excretion of 17-hydroxycorticosteroids occurred regularly. 2. Chromatographic analysis of the urinary corticoids revealed that the decreased urinary excretion involved exclusively cortisol metabolites, whereas corticosterone metabolites were excreted at normal levels. This chromatographic study moreover showed an impairment in the conjugation of tetrahydrocorticoids. 3. Studies with 4-14C-cortisol in MNT treated patients showed increased transcortin levels, a normal cortisol pool, a reduced cortisol inactivation rate and a decreased cortisol production. 4. From these results it is concluded that the decreased 17-hydroxycorticoid excretion reflects a decreased cortisol production, at least partly secondary to a reduced cortisol-inactivation rate, which itself must be attributable either to an inhibition or a defect in the liver enzyme systems concerned in corticoid-inactivation.