To gain insight into the mechanism by which steroidal hormones influence the development of canine prostatic hyperplasia, nuclear and cytosolic androgen- and estrogen-receptor content, as measured under exchange conditions by the binding of [(3)H]R1881 (methyltrienolone) and [(3)H]estradiol, respectively, were quantitated in the prostates of purebred beagles of known age. In young dogs with spo...