Androgen receptor in the rat brain--assays and properties.

The existence and relevance of an androgen receptor in the developing brain has been a matter of controversy. We here describe both sucrose density gradient and hydroxylapatite assays which clearly define a distinct androgen receptor in the 24-day-old rat hypothalamus, amygdala and preoptic region, but not in the cortex. This receptor has considerable affinity for estradiol-17beta, thus perhaps accounting for some uncertainty about its nature, but none for diethylstilbestrol or other estrogens, antiestrogens or glucocorticoids. Its Kd for both dihydrotestosterone and testosterone is about 1 X 10(-9) M and for estradiol about 2 X 10(-8) M. Its properties are generally consistent with those of androgen receptor reported for other tissues.