A drug or substance that binds to a receptor inside a cell or on its surface and causes the same action as the substance that normally binds to the receptor. For instance, the active compounds tetrahydrocannabinol (THC), cannabidiol, cannabinol, and tetrahydrocannabivarin in the plant C. Sativa are physiological and psychoactive compounds. These active compounds are cannabinoid receptor agonists, meaning they stimulate the cannabinoid receptor to enhance its effect.
An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the agonist, while an inverse agonist causes an action opposite to that of the agonist.
English
Etymology
Borrowed from Latin agōnista, from Ancient Greek ἀγωνιστής (agōnistḗs, “combatant, champion”). By surface analysis, agon or agony + -ist.
Noun
agonist (plural agonists)
- Someone involved in a contest or battle (as in an agon), protagonist.
- The muscle that contracts while the other relaxes.
- (biochemistry, pharmacology) A molecule that can combine with a receptor on a cell to produce a physiological reaction.
