Urinary 5α-Androstane-3α,17β-Diol Radioimmunoassay: A New Clinical Evaluation*

Abstract

A rapid specific and reliable RIA for urinary 5α-androstane-3α,17β-diol (Adiol) is described using chromatographical purification and a specific antibody. Values are reported under some physiological and pathological conditions in 179 individuals. In 43 normal adult men, the mean (±SD) urinary Adiol excretion was 193 ± 77 μg/24 h, and in 29 normal women it was 44 ± 23 μg/24 h. These values are significantly different (P < 0.01). In 49 hirsute women, urinary Adiol Excretion was elevated (137 ± 51 μg/24 h) and significantly different from this value in normal women (P < 0.01). The urinary Adiol excretion in 10 postmenopausal women was very low (<5 ug/24 h). In normal adult subjects, the theoretical contribution to urinary Adiol of the major secreted androgens was calculated. Whereas dehydroisoandrosterone and dehydroisoandrosterone sulfate yield the same amount of urinary Adiol in both sexes, testosterone is the main precursor of Adiol in men and androstenedione is the main precursor in normal premenopausal and hirsute women. However, the amount of Adiol recovered in the 24-h urine depends not only on the secretion rate of androstenedione and testosterone but is also related to the testosterone 5α-reductase activity present in androgen target cells, especially in sexual skin.