Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Drug-Receptor Interaction: Antagonist01:28

Drug-Receptor Interaction: Antagonist

An antagonist is a drug that binds strongly to a receptor without activating it. An antagonist prevents other molecules, such as neurotransmitters or hormones, from binding to the receptor and triggering a cellular response. Such interaction effectively hinders the normal physiological processes mediated by the receptor, resulting in various pharmacological effects depending on the specific receptor targeted.
Antagonists can be classified as competitive or noncompetitive based on their...
Combined Effects of Drugs: Antagonism01:30

Combined Effects of Drugs: Antagonism

The combined effects of drugs can result in various interactions, of which an important type is antagonism. Antagonism is a mechanism where one drug inhibits or counteracts the effects of another drug. Antagonism can occur through various means, including receptor binding, allosteric modulation, functional interaction, chemical reactions, and pharmacokinetic processes.
The most common type is receptor antagonism, where one drug acts as an antagonist to block the effects of another drug by...
Agonism and Antagonism: Quantification01:14

Agonism and Antagonism: Quantification

When drugs are administered, they can elicit either an agonist or antagonist effect on the body. Agonism occurs when a drug activates a specific receptor, triggering a biological response. On the other hand, antagonism happens when a drug binds to the same receptors but blocks their activation, thereby preventing a biological response.
To quantify these effects, researchers use a dose-response curve, which provides valuable information about the potency and efficacy of a drug. Potency refers to...
Drug-Receptor Interaction: Agonist01:25

Drug-Receptor Interaction: Agonist

Agonists are drugs that interact with specific receptors in the body to produce a biological response. When an agonist binds to a receptor, it activates or enhances the receptor's function, leading to physiological effects. The interaction between agonist drugs and receptors is crucial for their therapeutic action in various medical treatments.
Agonists can bind to receptors in different ways. Some agonists bind directly to the receptor's active site, mimicking the endogenous ligand's action.
The Two-State Receptor Model01:29

The Two-State Receptor Model

The two-state receptor model explains a drug's interaction with receptors, such as G protein-coupled receptors and ligand-gated ion channels, to induce or inhibit a biological response. When no natural ligands are present, a receptor exists in an equilibrium of inactive (Ri) and active (Ra) conformations. The inactive form does not produce a response, while the active form generates a basal effect known as constitutive activity.
The binding affinity of a drug determines its interaction with one...
Muscle Coordination and Action01:24

Muscle Coordination and Action

Muscle coordination is a complex and finely tuned process essential for smooth and purposeful movements like flexion, extension, adduction, abduction, and rotation. The human body orchestrates the actions of various muscles working in concert, each with a specific role. Four functional types describe how muscles work together: agonist, antagonist, synergist, and fixator.
Agonists
Agonist muscles, often called prime movers, are the primary muscles responsible for producing a specific movement.

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

International multi-stakeholder consensus statement on patient, carer and public involvement to enhance clinical trial integrity.

Accountability in research·2026
Same author

Ethics and informed consent in clinical trial integrity: An international, multi-stakeholder consensus statement by Cairo Consensus Group.

International journal of gynaecology and obstetrics: the official organ of the International Federation of Gynaecology and Obstetrics·2025
Same author

Endometriosis, progestogen, and depression: is there a way out?

Fertility and sterility·2025
Same author

International multistakeholder consensus statement on post-publication integrity issues in randomized clinical trials by Cairo Consensus Group.

International journal of gynaecology and obstetrics: the official organ of the International Federation of Gynaecology and Obstetrics·2025
Same author

PGT-A: what's it for, what's wrong?

Journal of assisted reproduction and genetics·2025
Same author

The dilemma of polycystic ovary syndrome and pregnancy complications.

Fertility and sterility·2024
Same journal

Confronting complexities of uterus transplantation: Balancing Innovation, Risk and Access.

Fertility and sterility·2026
Same journal

Fertility Benefits and Parental Leave Policies across Accreditation Council for Graduate Medical Education (ACGME) Programs with Ob/Gyn Residency Programs.

Fertility and sterility·2026
Same journal

Optimizing the therapeutic donor insemination cycle.

Fertility and sterility·2026
Same journal

Hormonal and metabolic effects of the administration of oral low-dose 17-β-estradiol (0.2 mg) in patients with Functional Hypothalamic Amenorrhea (FHA): A Retrospective Pilot Study.

Fertility and sterility·2026
Same journal

Biomarker or Bystander? Considering Triglyceride Glucose-Body Mass Index (TyG-BMI) in Patients with Polyendocrine Metabolic Ovarian Syndrome.

Fertility and sterility·2026
Same journal

The Importance of the Incubator: Perinatal Outcomes following Intravaginal Culture.

Fertility and sterility·2026
See all related articles

Related Experiment Video

Updated: May 25, 2026

Modeling Ligands into Maps Derived from Electron Cryomicroscopy
09:30

Modeling Ligands into Maps Derived from Electron Cryomicroscopy

Published on: July 19, 2024

Agonist and antagonist coast.

Mohamed Aboulghar1

  • 1The Egyptian IVF Center, Maadi, Cairo. ghar@link.net

Fertility and Sterility
|January 24, 2012
PubMed
Summary
This summary is machine-generated.

GnRH antagonist protocols significantly decrease OHSS incidence compared to GnRH agonists. Coasting and GnRH antagonist administration in high-risk patients effectively reduce OHSS rates during ovarian stimulation.

More Related Videos

A Kinetic Fluorescence-based Ca2+ Mobilization Assay to Identify G Protein-coupled Receptor Agonists, Antagonists, and Allosteric Modulators
07:41

A Kinetic Fluorescence-based Ca2+ Mobilization Assay to Identify G Protein-coupled Receptor Agonists, Antagonists, and Allosteric Modulators

Published on: February 20, 2018

Stepwise Dosing Protocol for Increased Throughput in Label-Free Impedance-Based GPCR Assays
06:13

Stepwise Dosing Protocol for Increased Throughput in Label-Free Impedance-Based GPCR Assays

Published on: February 21, 2020

Related Experiment Videos

Last Updated: May 25, 2026

Modeling Ligands into Maps Derived from Electron Cryomicroscopy
09:30

Modeling Ligands into Maps Derived from Electron Cryomicroscopy

Published on: July 19, 2024

A Kinetic Fluorescence-based Ca2+ Mobilization Assay to Identify G Protein-coupled Receptor Agonists, Antagonists, and Allosteric Modulators
07:41

A Kinetic Fluorescence-based Ca2+ Mobilization Assay to Identify G Protein-coupled Receptor Agonists, Antagonists, and Allosteric Modulators

Published on: February 20, 2018

Stepwise Dosing Protocol for Increased Throughput in Label-Free Impedance-Based GPCR Assays
06:13

Stepwise Dosing Protocol for Increased Throughput in Label-Free Impedance-Based GPCR Assays

Published on: February 21, 2020

Area of Science:

  • Reproductive Endocrinology
  • Infertility Treatments
  • Ovarian Stimulation Protocols

Background:

  • Gonadotropin-releasing hormone agonists (GnRH-a) in ovarian stimulation can lead to increased Ovarian Hyperstimulation Syndrome (OHSS) incidence.
  • Previous reviews showed no significant difference in OHSS rates between GnRH agonist and antagonist protocols, but recent evidence indicates a significant decrease with antagonist protocols.
  • Coasting is a common OHSS prevention strategy, typically initiated when the lead follicle reaches 16 mm and hCG is administered upon E2 levels dropping below 3000 pg/ml.

Purpose of the Study:

  • To evaluate the efficacy of GnRH antagonist protocols in reducing OHSS incidence.
  • To assess the role of GnRH antagonist administration in high-risk patients previously down-regulated with GnRH-a.
  • To analyze the effectiveness of GnRH antagonist treatment in patients who developed early OHSS.

Main Methods:

  • Comparison of OHSS rates between GnRH agonist and antagonist protocols for ovarian stimulation.
  • Administration of daily GnRH antagonist to high-risk patients pre-treated with GnRH-a.
  • Treatment of early OHSS cases with daily GnRH antagonist injections and embryo cryopreservation.

Main Results:

  • Recent Cochrane reviews demonstrate a highly significant decrease in OHSS incidence with GnRH antagonist protocols.
  • Daily GnRH antagonist administration in GnRH-a down-regulated, high-risk patients led to a rapid drop in E2 levels and reduced OHSS incidence.
  • In patients with early OHSS treated with GnRH antagonists, no progression to severe OHSS was observed, with all embryos cryopreserved.

Conclusions:

  • GnRH antagonist protocols are superior to GnRH agonist protocols in significantly reducing OHSS incidence.
  • GnRH antagonist administration is an effective strategy for preventing OHSS in high-risk patients and managing early-stage OHSS.
  • Embryo cryopreservation in conjunction with GnRH antagonist treatment offers a safe approach for patients experiencing early OHSS.