1.Location and removal of deslorelin acetate implants in female African lions (Panthera leo).
Moresco A;Dadone L;Arble J;Klaphake E;Agnew DW J Zoo Wildl Med. 2014 Jun;45(2):397-401.
Contraception is necessary to manage zoo animal populations and to be able to house animals in groups without producing additional unwanted offspring. In felids and canids, an association between exposure to progestins and the occurrence of endometrial and mammary gland pathology has been documented. Therefore, the Association of Zoos and Aquariums (AZA) Wildlife Contraceptive Center recommends the use of deslorelin acetate for long-term contraception in carnivores. Return to cyclicity after deslorelin treatment has been variable; some individuals show ovarian suppression for long periods after the expected end of the deslorelin efficacy. In an attempt to reduce the time to reversal, techniques to locate and remove previous implants are being developed. This report documents the successful implementation of high-frequency ultrasonography in lions (Panthera leo) to locate and direct surgical removal of multiple deslorelin implants placed at least 2 yr previously as well as the return of follicular activity in both females at 7 months post-removal of implants.
2.Deslorelin implants in pre-pubertal female dogs: short- and long-term effects on the genital tract.
Marino G;Rizzo S;Quartuccio M;Macrì F;Pagano G;Taormina A;Cristarella S;Zanghì A Reprod Domest Anim. 2014 Apr;49(2):297-301. doi: 10.1111/rda.12272. Epub 2014 Jan 27.
Deslorelin acetate is a GnRH agonist used for contraception in dogs. This study aimed to evaluate the treatment of pre-pubertal female dogs with deslorelin acetate implants, to better investigate the primary stimulatory effect of the drug and the long-term effects on the genital tract, throughout repeated treatments. Sicilian hound female dogs (24) were randomly assigned to treated group, control group 1 and control group 2. First group bitches were implanted at 4.5, 9.0 and 13.5 months and monitored clinically, ultrasonographically and endocrinologically, throughout the study period (13.5 months). Control group 1 bitches were not implanted and clinically monitored for the same period. At 18 months, the animals underwent ovariohysterectomy, thus allowing evaluation of the internal genitalia. Control group 2 bitches were ovariohysterectomized at the age of 4.5 months. The suppression of oestrus was obtained in the treated group despite the fact that the first implant caused a modest increase in plasmatic levels of 17-beta estradiol and an evident cornification of the vaginal mucosa cells (50-80%). Estradiol and progesterone were at baseline levels for the remaining study period, in which no other oestrous manifestations were observed.
3.Expression of GnRH receptor in the canine corpus luteum, and luteal function following deslorelin acetate-induced puberty delay.
Kaya D;Gram A;Kowalewski MP;Schäfer-Somi S;Kuru M;Boos A;Aslan S Reprod Domest Anim. 2017 Dec;52(6):1104-1112. doi: 10.1111/rda.13038. Epub 2017 Sep 30.
The goals of this study were as follows: (Experiment 1) to examine the basic capability of canine corpora lutea (CL) to respond to GnRH by assessing expression of gonadotropin-releasing hormone receptor (GnRH-R) in luteal samples collected throughout the luteal lifespan from non-pregnant dogs, and (Experiment 2) to investigate the effects of pre-pubertal application of the GnRH agonist deslorelin acetate on luteal function following the first oestrus. Mature CL were collected during the mid-luteal phase (days 30-45) from treated and control bitches. Transcript levels of several factors were determined: estrogen receptors (ESR1/ERα, ESR2/ERβ), progesterone (P4)-receptor (PGR), prolactin receptor (PRLR), PGE2-synthase (PTGES) and PGE2 receptors (PTGER2/EP2, PTGER4/EP4), vascular endothelial growth factor (VEGFA) and VEGF receptors (VEGFR1 and VEGFR2), cyclooxygenase 2 (COX2/PTGS2), steroidogenic acute regulatory protein (STAR) and 3β-hydroxysteroid dehydrogenase (3βHSD). Additionally, levels of Kisspeptin 1 (Kiss1) and its receptor (KISS1-R) were evaluated. Although generally low, GnRH-R expression was time dependent and was elevated during early dioestrus, with a significant decrease towards luteal regression.