Hypothesized effects of environmental antiandrogens on the hypothalamic-pituitary-testis axis. (A) In normal condition androgens as testosterone (T) and dihydrotestosterone (DHT) exert negative influence on secretion of LHRH and LH by the hypothalamus and the pituitary, respectively. (B) Antiandrogens compete with T and DHT for binding to the androgen receptor (AR). The impaired ability of testosterone (T) to bind AR weakens the inhibitory feedback of T on LHRH and LH production by preventing the hypothalamus and anterior pituitary from recognizing the presence of T. This results in hypersecretion of LH and increased production of T by Leydig cells. Blocking peripheral AR by antiandrogens inhibits androgen-mediated effects on target organs potentially resulting in incomplete masculinization and malformations of the male reproductive tract.
