title: Improvement in spermatogenic function after subcutaneous implantation of a capsule containing an aromatase inhibitor in four oligozoospermic dogs and one azoospermic dog with high plasma estradiol-17beta concentrations.
abstract: A capsule containing an aromatase inhibitor (4-androsten-4-ol-3,17-dione) was subcutaneously implanted in four oligozoospermic beagle dogs and one azoospermic beagle dog with high plasma estradiol-17beta (E2) concentrations (15-19 pg/ml) and low plasma testosterone (T) concentrations (0.6-0.8 ng/ml) for 8 weeks and the effect of the aromatase inhibitor on spermatogenic dysfunction was assessed. Plasma E2 and T concentrations and semen quality were examined at 1 week intervals from 3 weeks before to 12 weeks after the start of treatment. Testicular biopsies were done twice (capsule implantation and removal). Plasma E2 concentrations of all dogs decreased (9-14 pg/ml) and plasma T concentrations increased (2.0-2.6 ng/ml) from 3 weeks after capsule implantation to capsule removal. The mean number of spermatozoa ejaculated by all four oligozoospermic dogs between 4 and 9 weeks after implantation was higher (127 x 10(6) to 205 x 10(6)) than before implantation (20 x 10(6) to 38 x 10(6)) (P < 0.05 and 0.01). Very low numbers (2 x 10(4) to 4 x 10(4)) of immotile spermatozoa were observed between 7 and 8 weeks after implantation in the semen collected from the dog with azoospermia. Before implantation, a few spermatozoa were seen in only one-fifth of the seminiferous tubules in this dog; 8 weeks after implantation, the mean diameter and mean number of round spermatids in the seminiferous tubules in all five dogs were higher than before implantation (P < 0.05). Implantation of the capsule containing the aromatase inhibitor in infertile dogs with abnormally high plasma E2 concentrations improved their spermatogenic function, concurrent with decreased plasma E2 and increased plasma T.
authors.affiliation: Department of Reproduction, Nippon Veterinary and Animal Science University, 1-7-1 Kyonan-cho, Musashino-shi, Tokyo 180-8602, Japan.
authors.forename: Eiichi
authors.initials: E
authors.lastname: Kawakami
authors.forename: Taichi
authors.initials: T
authors.lastname: Hirano
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Hori
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Tsutsui
mesh_terms: D000735:Androstenedione / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D047072:Aromatase Inhibitors; D004283:Dog Diseases / Q000097:blood / Q000188:drug therapy* / Q000473:pathology; D004285:Dogs; D004343:Drug Implants; D004958:Estradiol / Q000097:blood*; D008297:Male; D009845:Oligospermia / Q000188:drug therapy / Q000473:pathology / Q000662:veterinary*; D012661:Semen / Q000502:physiology; D013076:Sperm Count; D013081:Sperm Motility; D013091:Spermatogenesis; D013737:Testis / Q000473:pathology; D013739:Testosterone / Q000097:blood
chemical_list: C488413:4-androsten-4-ol-3,17-dione; D047072:Aromatase Inhibitors; D004343:Drug Implants; D013739:Testosterone; D000735:Androstenedione; D004958:Estradiol