GnRH analogues--agonists and antagonists.

Area of Science:

• Veterinary Pharmacology
• Reproductive Biology
• Endocrinology

Background:

• Gonadotropin-releasing hormone (GnRH) analogues are extensively used for animal reproduction control.
• Over 2000 analogues have been developed in the past 30 years, with varying potencies and effects.
• Continuous administration of potent GnRH agonists can paradoxically induce anti-fertility effects.

Purpose of the Study:

• To review the development and clinical applications of GnRH analogues in animal reproduction.
• To compare the efficacy and limitations of GnRH agonists and antagonists.
• To highlight challenges and advancements in GnRH analogue design and delivery.

Main Methods:

• Review of scientific literature on GnRH analogue development and application.
• Analysis of factors influencing agonist potency and efficacy.
• Evaluation of GnRH antagonist properties, including receptor binding and side effects.

Main Results:

• GnRH agonists, like Deslorelin, show high potency and widespread clinical use for pro- or anti-fertility roles.
• Agonist potency evaluation varies significantly based on the model used.
• GnRH antagonists have been developed with improved safety profiles, but their production cost remains a barrier.

Conclusions:

• GnRH agonists are clinically established for animal reproductive management.
• GnRH antagonist development has progressed slower than agonists, partly due to higher production costs.
• Parenteral delivery is necessary for synthetic GnRH analogues due to poor oral bioavailability.