Practice question

Vinclozolin is fungicide used on fruits and vegetables metabolized in vivo to two active metabolites M1 and M2 capable of competitive androgen receptor antagonism. These metabolites bind androgen receptor ligand-binding domain displacing dihydrotestosterone, preventing receptor dimerization, nuclear translocation and activation of androgen-responsive genes necessary for Wolffian duct maintenance, prostate development and external genitalia masculinization. Male rats exposed gestationally develop shortened anogenital distance, retained nipples, cryptorchidism and hypospadias. Vinclozolin does not interact with estrogen or thyroid receptors primarily but inhibits testosterone receptors via antiandrogenic antagonism causing demasculinization.