Glossary of PharmacologyAntagonistDefinition:A ligand that binds to the receptor but does not elicit any biological response and prevents the biological response elicited by an agonist. Antagonists do not trigger a conformational change in the receptor that initiates signalling cascades or translates into a biological effect. Example: Atenolol is an antagonist that binds to β1-adrenergic receptor in the heart and elicits no biological response, but it blocks the tachycardic action of catecholamines on the heart leading to a reduction in heart rate. |