Differentiation of androgen and oestrogen receptor mediated testosterone effects on FSH using androgen receptor deficient and normal mice

In the brain and pituitary of rodents two pathways of testosterone (T) action have to be considered. In the brain T is mainly aromatized to estrogens and acts via estrogen receptors (ER) (Schleicher et al., in press; Lieberburg et al., 1977). In the pituitary T binds as dihydrotestosterone (DHT) or T to androgen receptors (AR) Lieberburg et al., 1977). Only the former pathway but not the latter is possible in androgen receptor deficient Tfm (testicular feminized) mice (Schleicher et al., in press). T lowers serum FSH in castrated normal mice. To discriminate the pathways of this action, the effects of T on serum and pituitary FSH levels were examined in castrated Tfm mice and compared to castrated male and female mice.