1
|
Glocova K, Cizek P, Novotny R, Hauptman K, Tichy F. Effect of GnRH agonist deslorelin implant on spermatogenesis and testosterone concentration in Guinea pigs (Cavia aperea porcellus). Theriogenology 2020; 154:232-236. [PMID: 32679355 DOI: 10.1016/j.theriogenology.2020.05.038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 05/27/2020] [Accepted: 05/27/2020] [Indexed: 12/01/2022]
Abstract
Guinea pigs are social animals that are often kept in groups regardless of their gender. Due to reproduction control and male aggressiveness prevention, surgical castration is commonly required. In the present study, we evaluated the effect of GnRH agonist implant (4.7 mg deslorelinum) on the serum testosterone concentration (T) and spermatogenesis in male guinea pigs. Twenty-four animals were divided into two groups. All animals in the first group were neutered (Group 1), animals in the second group (Group 2) were administered the implant subcutaneously and then neutered in one-month intervals. A histological examination was performed when cross sections of seminiferous tubules were assessed. Subsequently, these tubules were divided based on the most developed germ cell observed: spermatogonia, spermatocytes, round spermatids, elongating spermatids and elongated spermatids. The anticipated decrease in testosterone concentration and cessation of spermatogenesis was not achieved. Thus, the results obtained proved the inefficacy of the deslorelin implant in male guinea pigs so the alternative methods of contraception remain the methods of choice.
Collapse
Affiliation(s)
- Kristyna Glocova
- Department of Anatomy, Histology & Embryology, Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Sciences, Brno, Palackeho 1946/1, 612 42, Czech Republic.
| | - Petr Cizek
- Department of Anatomy, Histology & Embryology, Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Sciences, Brno, Palackeho 1946/1, 612 42, Czech Republic
| | - Robert Novotny
- Ruminant & Swine Clinic, Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Sciences, Brno, Palackeho 1946/1, 612 42, Czech Republic
| | - Karel Hauptman
- Small Animal Clinic, Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Sciences, Brno, Palackeho 1946/1, 612 42, Czech Republic
| | - Frantisek Tichy
- Department of Anatomy, Histology & Embryology, Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Sciences, Brno, Palackeho 1946/1, 612 42, Czech Republic
| |
Collapse
|
2
|
Schoemaker NJ. Gonadotrophin-Releasing Hormone Agonists and Other Contraceptive Medications in Exotic Companion Animals. Vet Clin North Am Exot Anim Pract 2018; 21:443-464. [PMID: 29655478 DOI: 10.1016/j.cvex.2018.01.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The use of a gonadotrophin-releasing hormone agonist slow-release implant (GnRH A-SRI) has become increasingly popular as an alternative for surgical contraception in many species. Although these implants have proven to be very effective in some species (eg, ferrets, rats, chicken, psittacines, and iguanas), they have been found less effective in other species (eg, male guinea pigs and rabbits, veiled chameleons, slider turtles, and leopard geckos). This review provides an overview of the available literature on the effects of GnRH A-SRIs in companion exotic animals.
Collapse
Affiliation(s)
- Nico J Schoemaker
- Division of Zoological Medicine, Utrecht University, Yalelaan 108, Utrecht 3584 CM, Netherlands.
| |
Collapse
|
3
|
DOSE AND DURATIONAL EFFECTS OF THE GONADOTROPIN-RELEASING HORMONE AGONIST, DESLORELIN: THE MALE RAT (RATTUS NORVEGICUS) AS A MODEL. J Zoo Wildl Med 2013; 44:S97-101. [DOI: 10.1638/1042-7260-44.4s.s97] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
4
|
Smith AW, Asa CS, Edwards BS, Murdoch WJ, Skinner DC. Predominant suppression of follicle-stimulating hormone β-immunoreactivity after long-term treatment of intact and castrate adult male rats with the gonadotrophin-releasing hormone agonist deslorelin. J Neuroendocrinol 2012; 24:737-47. [PMID: 22172059 PMCID: PMC5559102 DOI: 10.1111/j.1365-2826.2011.02271.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
Gonadotrophin-releasing hormone (GnRH) agonists are used to treat gonadal steroid-dependent disorders in humans and to contracept animals. These agonists are considered to work by desensitising gonadotrophs to GnRH, thereby suppressing follicle-stimulating hormone (FSH) and luteinising hormone (LH) secretion. It is not known whether changes occur in the cellular composition of the pituitary gland after chronic GnRH agonist exposure. Adult male Sprague-Dawley rats were treated with a sham, deslorelin, or deslorelin plus testosterone implant for 41.0 ± 0.6 days. In a second experiment, rats were castrated and treated with deslorelin and/or testosterone. Pituitary sections were labelled immunocytochemically for FSHβ and LHβ, or gonadotrophin α subunit (αGSU). Deslorelin suppressed testis weight by two-thirds and reduced plasma FSH and LH in intact rats. Deslorelin decreased the percentage of gonadotrophs, although the effect was specific to the FSHβ-immunoreactive (-ir) cells. Testosterone did not reverse the deslorelin-induced reduction in the overall gonadotroph population. However, in the presence of testosterone, the proportion of gonadotrophs that was FSHβ-ir increased in the remaining gonadotrophs. There was no effect of treatment on the total LHβ-ir cell population, although the loss of FSHβ in bi-hormonal cells increased the proportion of mono-hormonal LHβ-ir gonadotrophs. The castration-induced plasma LH and FSH increases were suppressed by deslorelin, testosterone or both. Castration increased both LH-ir and FSH-ir without increasing the overall gonadotroph population, thus increasing the proportion of bi-hormonal cells. Deslorelin suppressed these increases. Testosterone increased FSH-ir in deslorelin-treated castrate rats. Deslorelin did not affect αGSU immunoreactivity, suggesting that the gonadotroph population per se is not eliminated by deslorelin, although the ability of gonadotrophs to synthesise FSHβ is compromised. We hypothesise that the FSH dominant suppression may be central to the long-term contraceptive efficacy of deslorelin in the male.
Collapse
Affiliation(s)
- Arik W. Smith
- Neurobiology Program and Department of Zoology and Physiology, University of Wyoming, 1000 E Univ. Ave., Dept. 3166, Laramie, WY 82071, USA
| | - Cheryl S. Asa
- Research Department, Saint Louis Zoo, 1 Government Drive, Saint Louis, MO 63110, USA
| | - Brian S. Edwards
- Neurobiology Program and Department of Zoology and Physiology, University of Wyoming, 1000 E Univ. Ave., Dept. 3166, Laramie, WY 82071, USA
| | - William J. Murdoch
- Reproductive Biology Program and Department of Animal Science, University of Wyoming, 1000 E Univ. Ave., Dept. 3684, Laramie, WY 82071, USA
| | - Donal C. Skinner
- Neurobiology Program and Department of Zoology and Physiology, University of Wyoming, 1000 E Univ. Ave., Dept. 3166, Laramie, WY 82071, USA
| |
Collapse
|
5
|
Arlt S, Spankowski S, Kaufmann T, Kostelnik K, Heuwieser W. Fertility control in a male rabbit using a deslorelin implant. A case report. WORLD RABBIT SCIENCE 2010. [DOI: 10.4995/wrs.2010.8190] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
|
6
|
Use of a gonadotropin releasing hormone agonist implant as an alternative for surgical castration in male ferrets (Mustela putorius furo). Theriogenology 2008; 70:161-7. [DOI: 10.1016/j.theriogenology.2008.03.006] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2007] [Revised: 03/05/2008] [Accepted: 03/09/2008] [Indexed: 11/23/2022]
|
7
|
Herbert CA, Trigg TE, Renfree MB, Shaw G, Eckery DC, Cooper DW. Effects of a Gonadotropin-Releasing Hormone Agonist Implant on Reproduction in a Male Marsupial, Macropus eugenii1. Biol Reprod 2004; 70:1836-42. [PMID: 14973259 DOI: 10.1095/biolreprod.103.025122] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
This study evaluated the potential of slow-release GnRH agonist (deslorelin) implants to inhibit reproductive function in the male tammar wallaby. The specific aim was to measure the effects of graded dosages of deslorelin on testes size and plasma LH and testosterone concentrations. Adult male tammar wallabies were assigned to four groups (n = 6 per group) and received the following treatment: control, placebo implant; low dose, 5 mg deslorelin; medium dose, 10 mg; high dose, 20 mg. All dosages of deslorelin induced acute increases (P < 0.001) in plasma LH and testosterone concentrations within 2 h, with concentrations remaining elevated during the first 24 h but returning to pretreatment levels by Day 7. Thereafter, there was no evidence of a treatment-induced decline in plasma testosterone concentrations. There was no detectable difference in basal LH concentrations between treated and control animals, nor was there a significant change in testes width or length (P > 0.05). These results suggest that the male tammar wallaby is resistant to the contraceptive effects of chronic GnRH agonist treatment. Despite the maintenance of testosterone secretion, the majority of male tammars (10 of 17) failed to respond to a GnRH challenge with a release of LH between Days 186 and 197 of treatment. The failure of animals to respond to exogenous GnRH suggests a direct effect of deslorelin on the pituitary, resulting in a level of desensitization that was sufficient to inhibit a LH surge but insufficient to inhibit basal LH secretion. The variation between animals is believed to result from earlier recovery of some individuals, in particular those that received a lower dose, or individual resistance to the desensitization process.
Collapse
Affiliation(s)
- C A Herbert
- Department of Biological Sciences, Macquarie University, North Ryde, New South Wales 2109, Australia.
| | | | | | | | | | | |
Collapse
|
8
|
Aspden WJ, Rao A, Rose K, Scott PT, Clarke IJ, Trigg TE, Walsh J, D'Occhio MJ. Differential responses in anterior pituitary luteinizing hormone (LH) content and LH beta- and alpha-subunit mRNA, and plasma concentrations of LH and testosterone, in bulls treated with the LH-releasing hormone agonist deslorelin. Domest Anim Endocrinol 1997; 14:429-37. [PMID: 9437579 DOI: 10.1016/s0739-7240(97)00048-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Anterior pituitary gland contents of LH and LH beta- and alpha-subunit mRNAs, and circulating concentrations of LH and testosterone, were determined in bulls treated with the LH-releasing hormone (LHRH) agonist deslorelin. Brahman (Bos indicus) bulls (14-month-old) were allocated to two groups and received the following: Control (n = 5), no treatment; Deslorelin (n = 4), four deslorelin implants (approximately 200 micrograms total deslorelin/day) for 36 d. Plasma concentrations of LH were higher in bulls treated with deslorelin on Day 1, had returned to typical levels by Day 8, and did not differ for control bulls and bulls treated with deslorelin from Day 8 to Day 29. Pituitary content of LH on Day 36 was reduced (P < 0.001) in bulls treated with deslorelin (33 +/- 4 ng/mg) compared with control bulls (553 +/- 142 ng/mg). Relative pituitary content of LH beta-subunit mRNA was also reduced on Day 36 in bulls treated with deslorelin (Control, 0.65 +/- 0.10; Deslorelin, 0.22 +/- 0.04; P = 0.003). However, alpha-subunit mRNA relative content did not differ (Control, 0.73 +/- 0.15; Deslorelin, 1.06 +/- 0.12; P > 0.05). Plasma concentrations of testosterone were increased over the period of the experiment in the bulls treated with deslorelin compared with control bulls. This is the first demonstration of reduced pituitary content of LH beta-subunit mRNA and LH, and unaltered content of alpha-subunit mRNA, in bulls treated with LHRH agonist. This was associated with apparently typical plasma concentrations of LH and elevated plasma testosterone. The anterior pituitary in bulls treated with LHRH agonist, therefore, undergoes classical desensitization and downregulation, but plasma LH and testosterone are not suppressed.
Collapse
Affiliation(s)
- W J Aspden
- CSIRO Tropical Agriculture, Tropical Beef Centre, Rockhampton Mail Centre, Queensland, Australia
| | | | | | | | | | | | | | | |
Collapse
|