[A measurement of 5-androstene-3 beta, 17 beta-diol in human serum (author's transl)]

A radioimmunoassay using specific antisera against 5-androstene-3 beta, 17 beta-diol-11 alpha-succinoyloxy-BSA was developed, and serum concentrations of 5-androstene-3 beta, 17 beta-diol (AD) in normal men and women (maternal vein during pregnancy and cord blood at delivery) were measured. The reliability of the method was assessed by means of the recovery rate (97-109%) and the co-efficient of variation of inter- and intra assay (10-14%). The concentrations in serum samples obtained from various sources were as follows (ng/ml of free steroid mean +/- SD): spermatic vein, 48.57 +/- 50.64, peripheral vein in men aged 57-84, 1.24 +/- 0.47; ovarian vein during follicular phase, 3.81 +/- 3.27, peripheral vein, 1.03 +/- 0.44; maternal vein at delivery, 3.03 +/- 0.77, umbilical artery, 6.58 +/- 3.00, umbilical vein, 6.32 +/- 2.82. Plasma AD levels in the spermatic and ovarian vein were significantly higher than in the peripheral vein, suggesting the gonadal secretion of this steroid. Maternal serum AD concentration increased as pregnancy advanced, and AD levels in cord blood at delivery were significantly higher than that in maternal blood. These results also indicate that AD is one of the products of the feto-placental unit.