Androgen receptor levels in patients with isolated hypospadias.

The binding of [3H]dihydrotestosterone (17 beta-hydroxy-5 alpha-androstan-3-one) to the androgen receptor was studied in 26 prepubertal boys with isolated hypospadias (no associated anomaly) using fibroblasts cultured from surgical specimens of hypospadiac penile skin and/or chordal tissue. Maximal binding capacities of androgen receptor for [3H] dihydrotestosterone in 10 patients with mild degree (2 glandular + 8 penile), 6 with severe degree (4 penoscrotal + 2 scrotal), chordal tissues of hypospadias (N = 10), and controls (10 endocrinologically normal boys) were, respectively, 11750 +/- 2410, 10720 +/- 2680, 16100 +/- 7570, and 11570 +/- 3830 (mean +/- sd) sites per cell. Dissociation constants in these subjects were 1.09 +/- 0.29, 0.93 +/- 0.22, 1.20 +/- 0.31, and 1.22 +/- 0.41 x 10(-10) mol/l respectively. There were no significant differences as to both maximal binding capacity and dissociation constant of androgen receptor among any groups. Abnormal receptor thermolability was not found in 5 patients with severe degree of hypospadias either. It is, therefore, concluded that prepubertal boys with isolated hypospadias have primarily normal androgen receptor activity.