Androgen- and Estrogen-Receptor Content in Spontaneous and Experimentally Induced Canine Prostatic Hyperplasia

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Abstract

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 [3H]R1881 (methyltrienolone) and [3H]estradiol, respectively, were quantitated in the prostates of purebred beagles of known age. In young dogs with spontaneously arising and experimentally induced (androstanediol plus estradiol treatment) prostatic hyperplasia, nuclear, but not cytosolic, prostatic androgen-receptor content was significantly greater than that determined in the normal prostates of age-matched dogs (3,452±222 and 4,035±274 fmol/mg DNA vs. 2,096±364 fmol/mg DNA, respectively). No differences were observed between the androgen-receptor content of the normal prostates of young dogs and the hyperplastic prostates of old dogs. The cytosolic and nuclear estrogen-receptor content of spontaneously arising prostatic hyperplasia in both young and old animals was similar to that found in normal prostates. The administration of estradiol plus androstanediol to castrate dogs significantly increased the prostatic nuclear androgen-receptor content over that found in dogs treated only with androstanediol. This estradiol-associated increase in nuclear androgen-receptor content was accompanied by the development of benign prostatic hyperplasia.

Authors

John Trachtenberg, L. Louise Hicks, Patrick C. Walsh