Study of the effect of an anti-androgen (Oxendolone) on experimentally induced canine prostatic hyperplasia

Summary

The results of hormonal investigation of effects of an antiandrogen, Oxendolone (OXD), alone or in combination with medroxyprogesterone acetate (MPA), on experimentally induced canine BPH are reported. Seventeen beagle dogs were divided into 5 groups: 2 castrate controls for. Group 0, 3 BPH controls for Group 1 which received 3α-androstanediol (3α-A) and estradiol (E₂) for one year, and 12 dogs consisting of 3 groups which received 3α-A and E₂ for 6 months followed by testosterone propionate (TP) and E₂ for another 6 months. The last 3 groups were treated with either 200 mg/week of OXD (Group 3) or OXD+30 mg/week of MPA (Group 4), and otherwise untreated with these hormones (Group 2, T-E controls). On the blood hormone analysis, both T and 5α-dihydrotestosterone (DHT) were generally lowered in the T-E administered groups (Group 2, 3 and 4) compared to those in Group 1. While MPA significantly descreased these androgen levels, OXD did not influence at all. The concentrations of E₂ were similar. Although T content in the prostate did not differ significantly within the experimental groups, DHT was the highest in Group 1 and the lowest in Group 4 and was nearly the same level to Group 0. MPA reduced tissue DHT content but OXD did not. In the receptor assay study, nuclear androgen receptor (AR) content in Group 3 and 4 was significantly lower than that in Group 1. No obvious decrease in nuclear AR content could be seen among the other groups. Significant differences were not observed in both the cytosol AR contents and in the cytosol and nuclear estrogen receptor (ER) contents, although they were generally low in Groups 3 and 4.