A MAJOR PATHWAY OF ADRENAL C19-Δ5-STEROID METABOLISM UNDER CONDITIONS OF STRESS: FORMATION OF 16α-HYDROXYANDROST-5-ENES

Abstract

ABSTRACT Changes in urinary steroid metabolites, following moderate and major surgery, have been investigated in 10 patients. In the majority of cases decreases in 17-ketosteroids were observed 7 days post-operatively and these were paralleled by an increase in 16-hydroxyandrost-5-enes (androst-5-ene-3β,16α-diol-17-one and androst-5-ene-3β,16α,17β-triol). The ratio of 16-hydroxyandrost-5-enes to the sum of 17-ketosteroids plus 16-hydroxyandrost-5-enes increased from an average of 0.24 pre-operatively to 0.58 post-operatively, in these cases. When corrections were made for losses, the increase in 16α-hydroxyandrost-5-enes ranged from 0.5 to 4.0 mg per 24 hours (average 2.0 mg). One patient was followed for a period of 15 months after radical mastectomy and post-operative radiotherapy. Substantial increases in urinary 16α-hydroxyandrost-enes occurred up to 9 weeks post-operatively. The levels subsequently decreased, but increased again when recurrence and plural effusion occurred. A linear relationship between the level of urinary 17-hydroxycorticosteroids and the sum of 17-ketosteroids and 16α-hydroxyandrost-5-enes was found over this time period. It is evident that the lowered levels of 17-ketosteroids observed in conditions of stress can be explained by altered metabolic pathways – one major pathway being the formation of 16α-hydroxy-androst-5-enes.