Morphological Study of the Effects of the GnRH Superagonist Deslorelin on the Canine Testis and Prostate Gland

Abstract

The present study is part of a programme of research designed to evaluate the efficacy of the GnRH superagonist,deslorelin (D-Trp6-Pro9-des-Gly10-LHRH ethylamide), as a contraceptive for male dogs. Adult dogs were assigned to a completely randomized design comprising six groups of four animals. Each dog in the control group received a blank implant (placebo) and each dog in the other five groups received a 6 mg deslorelin implant. One group of deslorelin treated dogs was sacrificed on each of days 16, 26, 41, 101 and 620, and testicular and prostate tissues were collected for study by light and electron microscopy. On days 16 and 26 after implantation, we observed partial disruption of the seminiferous tubules, with early spermatids shed into the lumen. On days 41 and 101 after implantation, 90–100% of the seminiferous tubules were atrophic and aspermatogenic.On day 101 after implantation, 99% of all sections showed atrophy of the epithelium and shrinkage of epithelial height in the ductus epididymides. On days 41 and 101 after implantation, prostate tissue showed complete atrophy of the glandular epithelium (100% of sections) and an apparent increase in the relative proportion of connective tissue. At the electron microscopic level, in dogs treated with deslorelin for 41 and 101 days, the Sertoli cells were smaller and their nucleoli appeared smaller than in the control dogs. The nucleoli of the Leydig cells were atrophied and prostate glandular epithelium showed reduced epithelial height, a trophy of the nucleolus and an absence of secretory granules.Tissues collected during the recovery phase revealed a complete recovery of spermatogenesis. In conclusion, slow release implants containing deslorelin induce a striking a trophy of the testes and prostate gland by 26 days after implantation, explaining the previously reported loss of ejaculate and arrest of sperm output. At histological level,the entire process appears to be completely reversible, in accordance with data on endocrine variables and semen production.

Alarelin active immunization influences expression levels of GnRHR, FSHR and LHR proteins in the ovary and enhances follicular development in ewes

“…No quantitative research has been described (Zamaratskaia et al 2007;Zapletal & Pavlik 2008;Junaidi et al 2009). No quantitative research has been described (Zamaratskaia et al 2007;Zapletal & Pavlik 2008;Junaidi et al 2009).…”

Biology and Diseases of Dogs

“…In pure cases of BPH, castration results in involution of the prostate gland detectable by rectal palpation within 7-10 days. This is available in a sustained release subcutaneous implant, which has demonstrated efficacy in reducing prostatic size in dogs (Junaidi et al, 2009). The alternative to castration is hormonal therapy, primarily with estrogens.…”

Semen Quality and Onset of Sterility Following Administration of a 4.7‐mg Deslorelin Implant in Adult Male Dogs

“…() reported that sterility was achieved by day 48 post‐treatment, while histologically Junaidi et al. () observed complete atrophy of seminiferous epithelium in the testicles of 90% of treated dogs at 41‐day post‐treatment. In the study of Junaidi et al.…”