Does testosterone diffuse down the wolffian duct during sexual differentiation?

Abstract

Sexual differentiation in gonadal dysgenesis is commonly asymmetrical. In patients with true hermaphroditism there may be an ovary and müllerian duct on 1 side, and a testis and wolffian duct on the other side. Such asymmetry suggests that testicular hormones only act locally at this early stage of sexual differentiation. We tested the hypothesis that testosterone reaches the wolffian duct by transport down the duct rather than by simple diffusion. Mouse 14-day urogenital ridges were placed in organ culture and microinjected with testosterone-albumin-fluorescein isothiocyanate. At 17 hours fluorescence was found throughout the wolffian duct and by 48 hours it was maximal in the dilated caudal end. Our results support the hypothesis that androgens may be transported along the wolffian duct. Secretion of testicular hormones into the wolffian duct may maintain hormone levels in the biologically active range.