Changes in androgen receptor, estrogen receptor alpha, and sexual behavior with aging and testosterone in male rats

摘要: Reproductive aging in males is characterized by a diminution sexual behavior beginning middle age. We investigated the relationships among testosterone, androgen receptor (AR) and estrogen alpha (ERα) cell numbers hypothalamus, their relationship to performance male rats. Young (3 months) middle-aged (12 rats were given tests, then castrated implanted with vehicle or testosterone capsules. Rats tested again for behavior. Numbers of AR ERα immunoreactive cells counted anteroventral periventricular nucleus medial preoptic nucleus, serum hormones measured. Middle-aged intact had significant impairments all measures compared young males. After castration implantation, behaviors largely comparable those In density was significantly (5-fold) higher, (6-fold) lower, testosterone- than vehicle-treated males, no age differences. Thus, restoration levels resulted similar concomitant reinstatement most behaviors. These data suggest that age-related differences cannot be due absolute further, brain retains capacity respond exogenous changes hypothalamic expression. Our finding replacement has profound effects on receptors potential medical implications treatment hypogonadism men.