EFFECTS OF GONADOTROPIN-RELEASING HORMONE ANTAGONIST DEGARELIX ON MUSTH AND SERUM TESTOSTERONE CONCENTRATIONS IN ASIAN ELEPHANTS (ELEPHAS MAXIMUS)

2018 ◽  
Vol 49 (3) ◽  
pp. 779-783
Author(s):  
Indunil N. Pathirana ◽  
Chandana Rajapaksa ◽  
Noritoshi Kawate ◽  
Anuradha Wimalarathne ◽  
Lakshitha Fonseka ◽  
...  
Keyword(s):  
Serum Testosterone ◽  
Gonadotropin Releasing Hormone ◽  
Elephas Maximus ◽  
Asian Elephants ◽  
Releasing Hormone

Potential of a gonadotropin-releasing hormone vaccine to suppress musth in captive male Asian elephants (Elephas maximus)

2016 ◽  
Vol 164 ◽  
pp. 111-120 ◽  
Author(s):  
Chaleamchat Somgird ◽  
Pongpon Homkong ◽  
Supaphen Sripiboon ◽  
Janine L. Brown ◽  
Tom A.E. Stout ◽  
...  
Keyword(s):  
Gonadotropin Releasing Hormone ◽  
Elephas Maximus ◽  
Asian Elephants ◽  
Releasing Hormone

SUPRESSION OF TESTICULAR FUNCTION IN A MALE ASIAN ELEPHANT (ELEPHAS MAXIMUS) TREATED WITH GONADOTROPIN-RELEASING HORMONE VACCINES

2014 ◽  
Vol 45 (3) ◽  
pp. 611-619 ◽  
Author(s):  
Imke Lueders ◽  
Thomas Bernd Hildebrandt ◽  
Charles Gray ◽  
Stephan Botha ◽  
Peter Rich ◽  
...  
Keyword(s):  
Gonadotropin Releasing Hormone ◽  
Asian Elephant ◽  
Elephas Maximus ◽  
Testicular Function ◽  
Releasing Hormone

EFFECTS OF A GONADOTROPIN-RELEASING HORMONE VACCINE ON OVARIAN CYCLICITY AND UTERINE MORPHOLOGY OF AN ASIAN ELEPHANT (ELEPHAS MAXIMUS)

2012 ◽  
Vol 43 (3) ◽  
pp. 603-614 ◽  
Author(s):  
Nancy C. Boedeker ◽  
Lee-Ann C. Hayek ◽  
Suzan Murray ◽  
David M. de Avila ◽  
Janine L. Brown
Keyword(s):  
Gonadotropin Releasing Hormone ◽  
Asian Elephant ◽  
Elephas Maximus ◽  
Releasing Hormone ◽  
Ovarian Cyclicity

Phage constructs targeting gonadotropin-releasing hormone for fertility control: evaluation in cats

2019 ◽  
Vol 22 (8) ◽  
pp. 685-695
Author(s):  
Aime K Johnson ◽  
Rebecca L Jones ◽  
Carol J Kraneburg ◽  
Anna M Cochran ◽  
Alexandre M Samoylov ◽  
...  
Keyword(s):  
Serum Antibody ◽  
Age Groups ◽  
Serum Testosterone ◽  
Phage Display Library ◽  
Gonadotropin Releasing Hormone ◽  
Testicular Volume ◽  
Future Research ◽  
Releasing Hormone ◽  
Half Dose ◽  
Group 3

Objectives Phage–gonadotropin-releasing hormone (GnRH) constructs with potential contraceptive properties were generated in our previous study via selection from a phage display library using neutralizing GnRH antibodies as selection targets. In mice, these constructs invoked the production of antibodies against GnRH and suppressed serum testosterone. The goal of this study was to evaluate this vaccine against GnRH for its potential to suppress reproductive characteristics in cats. Methods Sexually mature male cats were injected with a phage–GnRH vaccine using the following treatment groups: (1) single phage–GnRH vaccine with adjuvant; (2) phage–GnRH vaccine without adjuvant and half-dose booster 1 month later; or (3) phage–GnRH vaccine with adjuvant and two half-dose boosters with adjuvant 3 and 6 months later. Anti-GnRH antibodies and serum testosterone, testicular volume and sperm characteristics were evaluated monthly for 7–9 months. Results All cats developed anti-GnRH antibodies following immunization. Serum antibody titers increased significantly after booster immunizations. In group 3, serum testosterone was suppressed 8 months after primary immunization. Total testicular volume decreased in group 1 by 24–42% and in group 3 by 15–36% at 7 months after immunization, indicating potential gonadal atrophy. Vacuolation of epididymides was observed histologically. Although all cats produced sperm at the conclusion of the study, normal morphology was decreased as much as 38%. Phage alone produced no local or systemic reactions. Immunization of phage with AdjuVac produced unacceptable injection site reactions. Conclusions and relevance Our phage-based vaccine against GnRH demonstrated a potential for fertility impairment in cats. Future research is required to optimize vaccine regimens and identify animal age groups most responsive to the vaccine. If permanent contraception (highly desirable in feral and shelter cats) cannot be achieved, the vaccine has a potential use in zoo animals or pets where multiple administrations are more practical and/or reversible infertility is desirable.

scholarly journals Case Report: Suppression of Harem Stallion Behavior and Fertility Following Anti-Gonadotropin-Releasing Hormone Vaccination of a Captive Wild Przewalski's Horse (Equus ferus przewalskii)

2020 ◽  
Vol 7 ◽  
Author(s):  
Jérôme Ponthier ◽  
Goulven Rigaux ◽  
Sonia Parrilla-Hernandez ◽  
Sophie Egyptien ◽  
Carine Gatez ◽  
...  
Keyword(s):  
General Anesthesia ◽  
Semen Quality ◽  
Serum Testosterone ◽  
Primary Vaccination ◽  
Gonadotropin Releasing Hormone ◽  
Field Methods ◽  
Releasing Hormone ◽  
Spermatozoa Motility ◽  
The Social

This report describes an option to modulate the testicular function of wild horses and field methods to assess it. Non-surgical castration of a captive wild Przewalski's stallion with anti-gonadotropin-releasing hormone (GnRH) immunization was performed by sub-cutaneous injection of two doses of 450 μg (3 ml) of GnRH conjugated to diphtheria toxin, further repeated every 6 months. Semen quality was assessed after collection by electro-ejaculation under general anesthesia. Endocrine and behavioral consequences were studied during a 2-year follow-up period. The procedure of electro-ejaculation was safe and effective to collect spermatozoa. Motility was low but was improved by a significant dilution of sample (1v/4v−1v/5v) after collection. Immuno-neutering resulted in a decrease of the total spermatozoa number and motility 1 month after primary vaccination. However, infertility could not yet be guaranteed. Six months post-vaccination, serum testosterone concentrations had decreased and the treated stallion had lost his harem stallion role. Moreover, at the same time, the total spermatozoa number was near zero with no motile spermatozoa, and offspring was no longer observed. As a conclusion, electro-ejaculation under general anesthesia is suitable on wild horses to obtain spermatozoa that should be washed or largely diluted before use for artificial insemination (AI) programs. Anti-GnRH immuno-neutering protocol led to a dramatic decrease of spermatozoa number, motility, and testosterone production. This also induced deep changes in the social structure of the band. Such technique could be considered as an alternative to surgical castration in wild horses.

scholarly journals Recent Advances in the Management of Metastatic Prostate Cancer

2021 ◽  
pp. OP.21.00206
Author(s):  
Nicolas Sayegh ◽  
Umang Swami ◽  
Neeraj Agarwal
Keyword(s):  
Prostate Cancer ◽  
Metastatic Prostate Cancer ◽  
Standard Of Care ◽  
Serum Testosterone ◽  
Gonadotropin Releasing Hormone ◽  
Novel Agents ◽  
Prostate Specific Membrane Antigen ◽  
Castration Resistant Prostate Cancer ◽  
Releasing Hormone ◽  
Specific Membrane

Management of metastatic prostate cancer has undergone a revolution over the past decade with the introduction of several novel agents and repurposing of others. Several clinical trials reported improved outcomes with the intensification of androgen deprivation therapy by the addition of docetaxel chemotherapy or novel hormonal agents (abiraterone, enzalutamide, or apalutamide) in the metastatic castration-sensitive state. Relugolix has been recently approved as the first oral gonadotropin-releasing hormone receptor antagonist agent with a superior cardiovascular side-effect profile, and serum testosterone suppression compared with a gonadotropin-releasing hormone agonist, leuprolide. Poly-ADP ribose polymerase inhibitors (olaparib and rucaparib) have demonstrated significant clinical benefit for patients harboring deleterious mutations in genes belonging to the homologous recombination repair pathway and have received Food and Drug Administration approval. Recently, lutetium-177-prostate-specific membrane antigen-617 with standard of care treatment has shown to improve overall survival in men with advanced-stage prostate-specific membrane antigen–positive metastatic castration-resistant prostate cancer. These recent approvals, successes, and the ongoing investigation of multiple novel agents are expected to continue to dramatically improve survival outcomes of men with metastatic prostate cancer in the coming years.

Leuprolide: A Gonadotropin-Releasing Hormone Analog for the Palliative Treatment of Prostatic Cancer

1986 ◽  
Vol 20 (10) ◽  
pp. 746-751 ◽  
Author(s):  
Norbert J. Wojciechowski ◽  
Charles A. Carter ◽  
Vasilios A. Skoutakis ◽  
David T. Bess ◽  
William J. Falbe ◽  
...  
Keyword(s):  
Gnrh Agonist ◽  
Prostatic Cancer ◽  
Palliative Treatment ◽  
Hot Flashes ◽  
Serum Testosterone ◽  
Gonadotropin Releasing Hormone ◽  
Subcutaneous Injections ◽  
Releasing Hormone ◽  
Gnrh Receptors ◽  
Hormone Analog

Leuprolide is the first member of the class of gonadotropin-releasing hormone (GnRH) agonist analog to be released in the U.S. The pharmacology of leuprolide is complex and not yet completely defined. This agonist analog is more potent than natural GnRH and appears to be capable of occupying pituitary GnRH receptors. This results in a “down regulation” of the receptors' activity and gonadotropin release, ultimately decreasing serum testosterone levels to those seen following castration. Leuprolide has been found effective in the palliative treatment of advanced cases of prostatic cancer and is not associated with the cardiovascular and thromboembolic toxicity seen with conventional diethylstilbestrol therapy. Leuprolide is administered by daily subcutaneous injections and has been generally well tolerated. The most common adverse effects are hot flashes and a possible flare-up of prostatic carcinoma symptoms on initial dosing. As clinical experience grows in the use of GnRH agonist analog, GnRH will assume a greater role in the treatment of metastatic prostatic cancer.

The association of polymorphism in gonadotropin releasing hormone with serum testosterone level during androgen-deprivation therapy and prognosis in metastatic prostate cancer.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e16570-e16570
Author(s):  
Masaki Shiota ◽  
Naohiro Fujimoto ◽  
Ario Takeuchi ◽  
Eiji Kashiwagi ◽  
Takashi Dejima ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Gene Polymorphism ◽  
Androgen Deprivation Therapy ◽  
Metastatic Prostate Cancer ◽  
Serum Testosterone ◽  
Gonadotropin Releasing Hormone ◽  
Androgen Deprivation ◽  
Serum Testosterone Level ◽  
Releasing Hormone ◽  
Testosterone Levels

e16570 Background: Serum testosterone suppression during androgen-deprivation therapy (ADT) have been reported to affect ADT efficacy. However, the factor affecting hormonal variations during ADT was less explored. Therefore, in this study, we investigated the missense polymorphisms in gonadotropin releasing hormone (GNRH) and hormonal variations during ADT as well as the prognosis among men treated with primary ADT for metastatic prostate cancer. Methods: This study included 80 Japanese patients with metastatic prostate cancer, whose serum testosterone levels during ADT were available. The association of the GNRH1 gene polymorphism (rs6185, S20W) and the GNRH2 gene polymorphism (rs6051545, A16V) with clinicopathological parameters including serum testosterone levels during ADT as well as the prognosis including progression-free survival and overall survival was examined. Results: The CT allele and the CT/TT alleles in the GNRH2 gene (rs6051545) were associated with higher serum testosterone levels during ADT compared with the CC allele. Consequently, the CT alleles was associated with higher progression risk after adjustment with age and serum testosterone levels during ADT [hazard ratio (95% confidence interval), 1.73 (1.00-3.00), P = 0.049]. Conclusions: Taken together, these findings suggested that genetic variation in rs6051545 ( GNRH2) may result in the inadequate suppression of on serum testosterone during ADT, which may lead to detrimental effect of ADT on prognosis among men with metastatic prostate cancer.

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