Drugs that bind to but do not activate Serotonin 5-HT4 RECEPTORS, thereby blocking the actions of Serotonin or Serotonin Receptor Agonists.

A substance that acts against and blocks an action. Antagonist is the opposite of agonist. Antagonists and agonists are key players in the chemistry of the human body and in pharmacology.

In medicine, a substance that stops the action or effect of another substance. For example, a drug that blocks the stimulating effect of estrogen on a tumor cell is called an estrogen receptor antagon [..]

antonym agonist Substance which binds to a cell receptor normally responding to a naturally occurring substance and which prevents a response to the natural substance.

Term used to refer to any substance that is used to stop something from happening by binding to a particular receptor that is responsible for that

1590s, from French antagoniste (16c.) or directly from Late Latin antagonista, from Greek antagonistes "competitor, opponent, rival," agent noun from antagonizesthai "to struggle agains [..]

A chemical entity that binds to a receptor and blocks its activation. Antagonists prevent the natural (or abused) substance from activating its receptor.

enemy or adversary.

See discussion under character, below.

In receptor-ligand interactions, an antagonist is a molecule that binds receptor, blocks the binding of agonist but fails to induce post-receptor signalling events.

A character or force against which another character struggles. Creon is Antigone's antagonist in Sophocles' play Antigone

a character or a nonhuman force that opposes or is in conflict with the protagonist.

Character whose dramatic role is to oppose the protagonist (q.v.).

 – the forces against the protagonist; could be another character, a force of nature, or an organization, or other entity or situation which creates opposition to protagonist

the main character, person, group, society, nature, force, spirit world, bad guy, or villain of a film or script who is in adversarial conflict with the film's hero, lead character or protagonist [..]

The character who opposes the main character (the protagonist).

 A drug or other molecule that blocks receptors. Antagonists inhibit the effects of agonists. 

n. 1. An agent, for example a drug or hormone, that works to reduce the action of an agonist - for example, by preventing an agonist agent from binding with a binding site. It may bind in a competitiv [..]

substance tending to nullify effects of another (pop)

An antagonist is a chemical or drug that binds to receptors in the brain and prevents an agonist from having a reaction. An inverse antagonist not only prevents an agonist from having a reaction on a [..]

the character who is a foil to the protagonist, providing the obstacle or opposing force against which the protagonist must work.

A molecule that blocks the activation of a receptor.

  A compound that inhibits the effect of an agonist in such a way that the combined biological effect of the two becomes smaller than the sum of their individual effects.

1. A molecule, usually a drug, that interferes with or prevents the action of a transmitter. Compare agonist (definition 1). 2. A muscle that counteracts the effect of another muscle. Compare agonist (definition 2) and synergist.

(n) someone who offers opposition(n) a muscle that relaxes while another contracts(n) a drug that neutralizes or counteracts the effects of another drug

One agent that opposes or fights the action of another. For example, insulin lowers the level of glucose (sugar) in the blood, whereas glucagon raises it; therefore, insulin and glucagon are antagonists.

The muscle opposing the major muscle required to do a task. It works to help balance movement and ward off injury.

Medication that counteracts the actions and properties of another.

Synonyms: inhibitor (in-HIB-eh-tur) Definition: (an-TAG-uh-nist) Counteracting or opposing. An antiandrogen would be an antagonist because it blocks the action of androgen. Compare to agonist.

An antagonist is an agent, usually a pharmaceutical product, which acts to inhibit a normal physiological response. For example, if an antagonist binds to a cell surface protein it will block the enzy [..]

A molecule that blocks the ability of a given chemical to bind to its receptor, preventing a biological response.

Illustrated Glossary of Organic Chemistry Antagonist: A drug having  a strong affinity for a receptor and little or no intrinsic activity when bound. For example, naloxone binds to (but does not stron [..]

a character that puts barriers and reversals in the way of a protagonist’s progress or objective.

a substance that counteracts or nullifies the biological effects of another, such as a compound that binds to a receptor but does not elicit a biological response.

Drugs that bind to but do not activate Serotonin 5-HT1 Receptors, thereby blocking the actions of Serotonin 5-HT1 Receptor Agonists. Included under this heading are antagonists for one or more of the [..]

Drugs that bind to but do not activate Serotonin 5-HT2 Receptors, thereby blocking the actions of Serotonin or Serotonin 5-HT2 Receptor Agonists. Included under this heading are antagonists for one or [..]

Drugs that bind to but do not activate Serotonin 5-HT3 RECEPTORS, thereby blocking the actions of Serotonin or Serotonin 5-HT3 Receptor Agonists.

Drugs that bind to but do not activate Adrenergic Receptors. Adrenergic antagonists block the actions of the endogenous adrenergic transmitters Epinephrine and Norepinephrine.

Drugs that bind to but do not activate Cholinergic Receptors, thereby blocking the actions of Acetylcholine or Cholinergic Agonists.

Drugs that bind to but do not activate GABA Receptors, thereby blocking the actions of endogenous gamma-Aminobutyric Acid and GABA Receptor Agonists.

Drugs that bind to but do not activate GABA-A Receptors thereby blocking the actions of endogenous or exogenous GABA-A Receptor Agonists.

Drugs that bind to but do not activate GABA-B Receptors thereby blocking the actions of endogenous or exogenous GABA-B Receptor Agonists.

Compounds that inhibit the action of Prostaglandins.

A drug or substance that nullifies the effect of another substance.

1.) A drug or other molecule that blocks receptors. Antagonists inhibit the effects of agonists. 2.) A muscle that moves a joint in opposition to an intended direction.

In medicine, a substance that stops the action or effect of another substance. For example, a drug that blocks the stimulating effect of estrogen on a tumor cell is called an estrogen receptor antagonist.

Oppose action of other medicines; binds to a receptor and prevents a response.  

Ligands that bind to the active site on a protein.

the main character in a work of fiction who comes into conflict with the protagonist (hero or heroine). Note that the antagonist does not always have to be a character; it could be a thing or a situat [..]

<pharmacology> A substance that tends to nullify the action of another, as a drug that binds to a cell receptor without eliciting a biological response. Origin: Gr. Antagonistes = an opponent (18 Nov 1997)

A drug which attenuates the effects of an agonist. Antagonism can be competitive and reversible (i.e. it binds reversibly to a region of the receptor in common with the agonist.) or competitve and irr [..]

An opponent or enemy. * Milton *: antagonist of Heaven's Almighty King * Hooker *: our antagonists in these controversies One who antagonizes or stirs. (biochemistry) A chemical that binds t [..]

The antagonist is the villain or nasty character in the novel that you root against. You know, the person who stands in the way of the protagonist.While many antagonists are garden variety Bad Guys, a [..]