A single acyline treatment significantly impairs canine spermatogenesis

H. KÖRBER ; A. FRIMØDT RONNOW; M.J. PAEZ LIZCANO; M. FAYA; C GOBELLO; S. GOERICKE-PESCH

Venecia

Congreso; XXI International Congress of European Veterinary Society for Small Animal Reproduction. 2018, Venice, Italia; 2018

European Veterinary Society for Small Animal Reproduction

The use of GnRH antagonists is discussed as a possible non-surgical approach to castration of male dogs and treatment of androgen-dependent diseases. A single acyline treatment in dogs rapidly and significantly suppressed gonadotropins and testosterone (T) temporarily and severely impaired testicular size and semen quality with increasing numbers of round spermatogenic cells in the ejaculate, as a sign for disruption of spermatogenesis [1-3]. However, data about histological changes in spermatogenesis are missing. Therefore, we investigated the effect of a single GnRH antagonist acyline treatment on canine spermatogenesis. Sexually mature male dogs (TG, n = 4) were treated with a single injection acyline (330 μg/kg) and surgically castrated two weeks later. Five untreated normospermic dogs served as controls (CG). Testicular tissue was fixated, embedded in paraffin, sections of 3-4 μm were cut and stained with Hematoxilin-Eosin. From each dog, 200 cross-sections of approximately round tubuli seminiferi contorti were evaluated for whether there was undisturbed spermatogenesis or spermatogenic arrest, followed by categorizing the different levels of arrest by the most developed germ cells observed. In case of full spermatogenesis being present, the different tubules were categorized in stages (Stage I-VIII), with stage II-IV been summarized in one group. Additionally, the presence or lack of the lumen was registered and the area of 100 round tubules from each dog was determined using the GNU Image Manipulation Program (GIMP). Statistical analyses were performed with GraphPad Prism v. 7.02 and p