Reproduction of androstenedione by skin in vitro and serum levels of gonadotrophins and androgens in men with hypospadias

The reduction of 4-[1,2-³H]androstene-3,17-dione (androstenedione) in vitro by scrotal skin was measured in samples from nine men (16-34 yr old) with hypospadias and from ten male control subjects. The reduction of androstenedione was also studied in axillary and upper arm skin of seven control subjects. Androstenedione was reduced to material with chromatographic characteristics of 5α-androstane-3,17-dione and to 3α- and 3β-hydroxy-5α-androstan-17-one. No difference in 5α-reductase activity (defined as the sum of these three metabolites formed) was found in scrotal skin from hypospadic and control men. The mean concentration of 5α-dihydrotestosterone in serum from men with hypospadias was lower than that in serum from control subjects (P<0.01). The mean ratio of the serum concentrations of testosterone and 5α-dihydrotestosterone was higher in hypospadic men than in control subjects (P<0.05). No differences between the two groups were found in the mean serum concentrations of LH, FSH, prolactin, dehydroepiandrosterone, androstenedione, testosterone or testosterone-binding globulin.