One who contends with another, especially in combat; an adversary; an opponent.
A muscle which acts in opposition to another; as a flexor, which bends a part, is the antagonist of an extensor, which extends it.
A medicine which opposes the action of another medicine or of a poison when absorbed into the blood or tissues.
Antagonistic; opposing; counteracting; as, antagonist schools of philosophy.
A drug that prevents or reverses the action of another drug.
The force or forces that stand in the protagonist's way. Antagonist is the dramatist's term for the protagonist's opponent in a story, sometimes confused with the term "villain." The antagonist is sometimes but not always a villain; but he's always opposed to the protagonist. In Scarface, Pacino's character is the protagonist; the law is the antagonist.
(1) A drug that blocks a receptor, preventing stimulation. (2) A muscle whose contraction opposes an intended movement.
A major character in a screenplay whose values or behavior conflict with those of the protagonist. Sometimes, the antagonist does not have to be personified, but can be the elements, society, etc.
Drug that binds cellular receptors, inhibiting a response.
a muscle that has an action opposite that of the prime mover (agonist) and yields to the movement of the prime mover; a substance which blocks a receptor site where a specific molecule (agonist) binds
A muscle that can provide an opposing action to the action of another muscle (the agonist) around a joint.
Antagonists are present in almost every play. They oppose what the main hero, or protagonist of the play is trying to accomplish.
Any drug that inhibits the action of a specific neurotransmitter. go to glossary index
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 molecule that blocks the ability of a given chemical to bind to its receptor, preventing a biological response.
Muscle that counteracts the agonist, lengthening when agonist muscle contracts.
a character that opposes the hero (-ine); villain.
a drug that has an opposite reaction or competes for the same thing
The bad person in a story; opposes the protagonist.
A molecule that prevents the action of other molecules, often by competing for a cellular receptor; opposite of agonist.
a pharmacological term referring to a substance that inactivates membrane receptors, inhibiting a cellular response.
the character who opposes the hero or heroine of a work.
1. Substance that reverses or reduces the effect induced by an agonist. 2. Substance that attaches to and blocks cell receptors that normally bind naturally occurring substances. AN agonist. anthelmint(h)ic: Substance intended to kill parasitic intestinal worms, such as helminths. SN antihelminth.
A drug that blocks or reverses the effect of another drug.
An herb or substance that opposes the action of some other agent or medicine, especially the toxic effects of alkaline poisons.
refers either to: (i) an agent that blocks the action of an agonist at its membrane receptor; or (ii) a muscle that opposes those muscles performing a specific movement around a joint. For example, the triceps muscle acts antagonistically to the biceps muscle in elbow flexion
A psychoactive drug that acts on the synapse between neurones and blocks the action of another drug
A drug that can bind with a receptor site in the brain, producing no pharmacological response but inhibiting the actions of agonists for that receptor. Examples: naltrexone at opioid receptors; buprenorphine, an opioid antagonist and a partial opioid agonist. See also agonist, pharmacotherapies
Oppose action of other medicines.
a Compound that inhibits the effect of the natural ligand of a certain receptor; the opposite of agonist.
In certain Greek tragedies, the opponent of the protagonist.
Any force that is in conflict with the protagonist. An antagonist may be another person, an aspect of the physical or social environment, or a destructive element in the protagonist's own nature ( SS 554).
someone who offers opposition
a muscle that relaxes while another contracts; "when bending the elbow the triceps are the antagonist"
a drug that neutralizes or counteracts the effects of another drug
a character or impediment that opposes the protagonist and creates conflict in a literary work
a character within a story
a chemical compound that competes with drugs such as cocaine for occupancy of the receptor
a drug or a compound that opposes the physiological effects of another
a drug that competes with opioid receptor sites
a drug that does not provoke a response itself, but blocks agonist-mediated responses
a ligand that binds to a receptor but does not produce a biological effect (direct acting) or a compound that indirectly inhibits the effect of a neurotransmitter (indirect acting)
a ligand that does not bring about a functional change when it binds to receptors
a molecule that blocks the effect that the neurotransmitter normally has on the post-synaptic neuron
a muscle acting AGAINST the direction of a movement
a substance that nullifies or blocks the action of another, but does so without causing a biologic response
a substance, which blocks and makes it difficult for the effects of other natural, narcotic or medicine substances to take place
a compound that will bind to a receptor to form a complex which does not give rise to any response, as if the receptor were unoccupied.
The main character or force in a fiction that tries to stop the protagonist (the hero or heroine of the story) from achieving his/her goal.
a character who seems to be the major force in opposition to the protagonist or main character
a substance that interferes with the physiological action of another substance
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 irreversible (i.e.antagonist binds covalently to the agonist binding site, and no amount of agonist can overcome the inhibition). Other types ofantagonism are non-competitive antagonism where the antagonist binds to an allosteric site on the receptor or an associated ion channel.
The muscle or muscles that perform the opposite motion of the agonist(s). See agonist above.
The character in a story that portrays the adversary, enemy, contender, or competitor to the protagonist.
When talking about drugs, this refers to a compound that opposes the activity of the cell receptors.
A substance that interferes or counteracts.
Muscles that counteract the action of the agonist muscles.
Something opposing or resisting the action of another. One of two muscles which pull in nearly opposite directions.
a drug that binds to receptors, inhibiting their function
The character (or force) in film or literary works that opposes the protagonist and leads to the dramatic conflicts.
a substance that inhibits the function of certain neuron receptor sites--opposite of agonist
the character or obstacle which stands against the protagonist or hero of the story. If you think of the main character as the "good guy", then the antagonist is the "bad guy" (or thing) with whom the hero is in conflict.
Villain or bad-guy who is in conflict with the protagonist.
A muscle that opposes the agonist, usually located on the opposite side of the joint.
A compound that will bind to a receptor to form a complex, which does not give rise to any response and competes with the agonist.
A molecule that prevents the activation of a receptor. See Agonist.
a drug that neutralizes the effect of another drug
A substance which reduces or prevents the effect of an agonist at a receptor site.
Substances, which bind to a receptor without inducing its activation and prevent receptor activation by an activating compound
A chemical that binds to a receptor and blocks it, producing no response, and preventing agonists from binding, or attaching, to the receptor. Antagonists include caffeine and naloxone.
In medicine, a substance that stops the action or effect of another substance. For example, a medication that blocks the stimulating effect of estrogen on a tumor cell is called an estrogen receptor antagonist.
A drug that binds to a cellular receptor and prevents its activation by the natural ligands and does not by itself elicit any biological response.
A muscle that produces an action that is exactly the opposite of the agonist.
The character (or force) opposing the protagonist; from the Greek word meaning Ã¢â‚¬Å“struggler against.
Blocker; an antagonist at a given receptor blocks or lowers the activity of that receptor.
Greek anti = against, and agonistes = rival, hence a muscle which may oppose an agonist.
In fiction, the main character who comes into conflict with the protagonist (hero or heroine). The antagonist could, in some stories, be a thing or situation (a monster, a storm, a flood, etc.).
Villain of the film or script who is in conflict with the protagonist.
a drug that counteracts or neutralizes another drug.
The major character in a narrative or drama who works against the hero or protagonist. An example of an evil antagonist is Richard Lovelace in Samuel Richardson's Clarissa, while a virtuous antagonist is Macduff in William Shakespeare's Macbeth.(Compare with protagonist.) (See also anti-hero, conflict.)
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 adversary of the main character; provides the obstacle the protagonist tries to overcome.
A chemical that acts within the body to reduce the physiological activity of another chemical substancei.e. opposing the action of a drug or a substance occurring naturally in the body by combining with and blocking its receptor
The major character in opposition to the hero or protagonist of a narrative or drama.
A drug or other molecule that blocks receptors. Antagonists inhibit the effects of agonists.
a substance that blocks the action of another substance by binding to the same receptor site.
the character who challenges the protagonist. This can be the villain or in a romance it might be the person of the opposite sex who is the protagonist or heroine's love interest. (See Step 4 for more details.)
a neutral term for a character who opposes the leading male or female character. See hero/heroine and protagonist.
the character who stands most directly opposed to the protagonist: his or her rival or enemy.
The protaganist's or hero's principal enemy.
A molecule which binds to a receptor and prevents the usual antagonist from binding. Haldol, for example, is a dopamine receptor antagonist.
The muscle that is directly opposite in movement to the agonist.
A muscle responsible for opposing the concentric muscle action of the agonist.
a character that puts barriers and reversals in the way of a protagonist's progress or objective.
in biochemistry, an antagonist acts against and blocks an action.
A substance which interferes with the functions of the brain's natural neurotransmitters
the character or force is main objective is to stop the protagonist (hero) from reaching their goal.
An agent or substance that counteracts the action of another. ()
A chemical compound whose physiological effect is the opposite of the effect created by the original molecule. For example, a dopamine antagonist has the opposite physiological effects from those of dopamine.
The antagonist muscle relaxes or lengthens while the agonist muscle contracts and is responsible for returning the body part to its anatomic position.
Colloquially referred to as the 'heavy' the antagonist is the character who is in direct opposition to the heroic figure or the protagonist
A chemical substance in the body that acts to reduce the physiological activity of another chemical substance.
A substance that opposes or alleviates the pharmacological effect of another compound.
That which counteracts the action of something else.
a drug that opposes the effects of another by physiological or chemical action or by a competitive mechanism.
A drug that blocks the action of another drug or substance in the body; insulin and glucagon are antagonists.
Any character in a story that opposes the efforts of the hero or main character (see Protagonist).
is the character, force, or collection of forces in fiction or drama that opposes the protagonist and gives rise to the conflict of the story; an opponent of the protagonist. Although the antagonist often acts against the protagonist, they do not have to be a villain, they can simply just be the character acting against the protagonist Example: In Othello, the antagonist would be Iago.
A chemical that competes for receptor binding sites with agonists.
n. a person who opposes, fights, or competes with another; opponent; rival.
blocks effects of another drug.
A drug or medication that prevents molecules of other drugs/medications from binding to a receptor (eg, an opioid receptor). Antagonists can also displace other opioids and can precipitate withdrawal, or block the effects of other opioids. Examples of antagonists include naltrexone and naloxone. | Close window
A muscle that acts in opposition to the action produced by an agonist muscle.
Chemical that blocks the action of a neurotransmitter
The villain or adversary, generally in conflict with the Protagonist.
A chemical that, when it binds to a receptor, blocks the receptor and prevents it from responding. Antagonists prevent agonists from binding, or attaching, to the receptor. Antagonists include caffeine and naloxone.
Antagonists block receptor sites. Medications used in the treatment of schizophrenia are antagonists because they block specific receptors in certain areas of the brain.
a drug which blocks the effects of opioid drugs.
A person, a situation, or the protagonist's own inner conflict in opposition to his or her goals.
A muscle that opposes the movement of an agonist.
(an-tag-o-nist): Medication, hormone, or neurotransmitter that acts against and blocks an action. For example, insulin lowers the level of glucose (sugar) in the blood, whereas another hormone called glucagon raises it; therefore, insulin and glucagon are antagonists.
the character or force whose opposition to the protagonist is the main source of conflict.
A chemical substance that opposes the action on the nervous system of a drug or a substance occurring naturally in the body, combining with and blocking its nervous system receptor.
a drug or a substance with opposite action to that of another drug or natural body chemical, which it inhibits.
A substance that tends to nullify the action of another.
a drug that has an affinity for a receptor but doesn't stimulate it and prevents a response from occurring.
(Muscle) Whose action opposes intended movement: (Drug) Molecule that competes with another for a receptor and binds to the receptor but does not trigger the cell's response
An agent that has the ability to bind to a receptor and prevent or block a response.
a substance that blocks a receptor from binding to a neurotransmitter or hormone.
An antagonist is a fictional character or group of characters, or, sometimes an institution of a story who represents the opposition against which the hero(es) or protagonist(s) must contend. In the classic style of story wherein the action consists of a hero fighting a villain, the two can be regarded as protagonist and antagonist, respectively.
An antagonist is a kind of muscle that acts in opposition to the movement generated by the agonist and is responsible for returning a limb to its initial position.