Effect of a new 5 alpha-reductase inhibitor on size, histologic characteristics, and androgen concentrations of the canine prostate

• Published in: The Prostate Vol. 3; no. 1; p. 35
• Main Authors: Brooks, J R, Berman, D, Glitzer, M S, Gordon, L R, Primka, R L, Reynolds, G F, Rasmusson, G H
• Format: Journal Article
• Language: English
• Published: United States 1982
• Subjects: 5-alpha Reductase Inhibitors; Animals; Atrophy - chemically induced; Azasteroids - pharmacology; Dihydrotestosterone - analogs & derivatives; Dihydrotestosterone - analysis; Dihydrotestosterone - pharmacology; Dogs; Dose-Response Relationship, Drug; Male; Organ Size - drug effects; Oxidoreductases - antagonists & inhibitors; Prostate - drug effects; Prostate - pathology; Spermatogenesis - drug effects; Steroids, Heterocyclic - pharmacology; Testosterone - analysis
• ISSN: 0270-4137
• DOI: 10.1002/pros.2990030107

Mature male beagles were used in studies designed to determine the effect of the steroidal 5 alpha-reductase inhibitor 17 beta-N,N-diethylcarbamoyl-4-aza-4-methyl-5 alpha-androstan-3-one (4-MA) on size, histology, and androgen concentration of the prostate. Subcutaneous administration of 3 or 15 mg/kg/day for 43 days caused a sharp decline in prostate volume. flattening of prostatic epithelial cells, vacuolization of the cytoplasm and pycnosis of the nuclei. Whereas serum testosterone levels remained normal in dogs injected with 3 mg/kg/day, they were lower in those that received 15 mg/kg/day. Concentration of both testosterone and 5 alpha-dihydrotestosterone were reduced in the prostates of dogs that had received either 3 or 15 mg/kg/day of 4-MA. The 15 mg/kg/day level also appeared to adversely affect spermatogenesis. In a 43-day study, 4-MA given orally once each day at levels of 0.1, 0.3, or 1 mg/kg failed to cause a significant decrease in prostate volume. However, daily divided oral doses totaling 1 or 3 mg/kg were given in a 42-day test and both treatment levels produced significant reductions in prostate size.