Androgen and estrogen receptor expression in the spinal segments of the genitofemoral nerve during testicular descent

Abstract

Aim During testicular descent (TD), the genitofemoral nerve (GFN) is masculinized by androgen. This study aimed to test whether androgen receptor (AR), estrogen receptor α (ERA), or estrogen receptor β (ERB) are expressed during TD in the GFN spinal segments and dorsal root ganglia (DRG) in normal and flutamide-treated rats. Methods Time-mated Sprague-Dawley dams were injected with flutamide (75 mg/kg, subcutaneously (S/C) in sunflower oil) on embryonic (E) days 16 to 19. Embryonic and postnatal (P) male L1-2 spinal cord segments were collected (E16, E17, E19, P0, P2, and P4) in control and flutamide-treated groups (n = 5-10). Samples were fixed in 4% paraformaldehyde. Five-micrometer-thick sections were prepared immunohistochemically for AR, ERA, and ERB. Results During TD, ERB was expressed in L1-2 DRG. Surprisingly, AR was not expressed in prenatal DRG, only after P2. There was no ERA expression. Flutamide had no effect on AR, ERB, or ERA expression in the L1-2 DRG during TD. Conclusion During the E window of androgen sensitivity, the GFN is not directly masculinized, with little AR expression and no change with flutamide over this period. Estrogen receptor β is expressed in the DRG during TD. However, its relevance is yet to be determined.