Evidence for age-dependent changes in Sertoli cell androgen receptor concentration

Cytosol and nuclear receptor concentrations in Sertoli cells isolated from the testes of 15-, 25-, and 35-day-old rats were measured using hydroxylapatite separation procedures. In these cells the mean Kd of the cytosol receptor for methyltrienolone (3H-R1881) ranged between 2.3 and 2.9 nM, and the concentration of cytosol androgen receptor per mg Sertoli cell DNA increased over the 15-to 35-day age interval. However, when the data were expressed per mg cytosol protein, no increase was observed. The increase in receptor concentration per mg DNA paralleled the increase in cytosol protein/DNA ratio. The concentration of androgen receptor per mg DNA in nuclear extracts also increased with age. Consequently, total Sertoli cell androgen receptor increases over the time interval in which meiosis is first completed in the testis.