Plasma 5±-Androstane-3±,17β-diol and Urinary 5±-Androstane-3±,17β-diol Glucuronide, Parameters of Peripheral Androgen Action: A Comparative Study*

Abstract

Both plasma 5α-androstane-3α,17β-diol (3αdiol) concentrations and urinary 5α-androstane-3α,17β-diol-glucuronide (3αdiol G) as well as 5β-androstane-3α,17β-diol-glucuronide (5β-3αdiol G) excretion levels were measured in 27 males and 22 females. To study the influence of age on these values, either plasma 3αdiol or urinary 3α- and 5β-3αdiol G levels were determined in an additional number of subjects. 3αdiol levels in plasma were significantly higher in young (60 yr old; 12.6 ± 1.2 ng/dl) males and in young (3.3 ± 0.4 ng/dl) than in postmenopausal women (2.4 ± 0.4 ng/dl). Similarly, in young men (<30 yr old), urinary excretion values of both 3αdiol G (80.6 ±7.1 jug/24 hr) and 5β-3αdiol G (266.2 ± 30.9 fig/24 hr) were significantly higher than those in males older than 60 yr (12.1 ± 1.5 and 56.7 ± 8.1 jug/24 hr, respectively), whereas postmenopausal women had significantly lower excretion values of both 3αdiol G (5.8 ± 0.5 jug/24 hr) and 5β-3αdiol G (17.3 ± 4.3 jug/24 hr) than women in reproductive life (12.8 ± 0.9 and 48.2 ± 5.4 jug/24 hr, respectively). In all women with simple hirsutism, increased plasma levels and urinary excretion values of adiols were found. In all groups studied, 5β-3αdiol G excretion values parallelled 3αdiol G excretion levels. A significant positive linear correlation between plasma 3αdiol and urinary 3adiol G levels was only found in young men. In males having undergone adrenalectomy for Cushing's disease, plasma 3αdiol levels were normal, whereas urinary 3α- and 5β-3αdiol G excretion were significantly lower than in agematched controls. After prolonged adrenal stimulation in normal males, urinary 3αdiol G rose to very high levels, while plasma 3αdiol remained within the normal range. Our data suggest that urinary 3αdiol glucuronide has a combined splanchnic and extrasplanchnic origin, whereas plasma 3αdiol is principally a metabolite of extrahepatic origin. Therefore, as well as for methodological reasons, plasma 3αdiol is to be recommended as a parameter of peripheral androgen action.