A drug that binds to a receptor of a cell and triggers a response by the cell.
In pharmacology, a substance that promotes, stimulates or mimics a receptor-mediated biological response by binding to the cell receptors. Contrast with antagonist.
A muscle that is a prime mover, directly responsible for a particular action.
Substance that binds and activates a membrane receptor.
In pharmacology, a drug that increases the action of another drug or a naturally produced body chemical.
Drugs that trigger an action from a cell or another drug.
The muscle in a muscle pair that is actively contracting at any given time to move the bone. It is also called the prime mover.
Small protein or organic molecules that bind to certain proteins (i.e., receptors) at a site that is adjacent to the active site of the protein (i.e., receptor) to induce a conformational change in that protein, thus enhancing its activity.
A muscle which causes part of the body to move and another muscle to relax when it contracts.
A substance which produces an observable physiological effect by acting through specific receptors.
A compound that enhances the activity of another compound in the body.
Pharmacological agent that combines with receptors to initiate drug actions.
A substance responsible for triggering a response in a cell. Agonist drugs are sometimes called mimics because they mimic part of the normal activity within a cell. Agonist drugs work by enhancing or restoring a cell’s normal activity.
A muscle whose active contraction causes movement of a part of the body. Contraction of an agonist is associated with relaxation of its antagonist.
The muscle that directly produces a specific action. In bending the elbow, the biceps brachii is the agonist and the triceps the antagonist.