Käänteisagonisti

Käänteisagonisti is a Finnish term that translates to "inverse agonist" in English. In pharmacology, an inverse agonist is a type of ligand that binds to the same receptor as an agonist but induces a pharmacological response opposite to that of the agonist. While a neutral antagonist blocks the action of an agonist, an inverse agonist actively reduces the basal activity of a receptor. This means that in the absence of any other ligand, an inverse agonist will decrease the receptor's activity below its baseline level.

Receptors are often considered to have a certain level of constitutive activity, meaning they can be active even without a ligand binding to them. An agonist increases this activity, a neutral antagonist has no effect on basal activity, and an inverse agonist decreases it. This property is crucial in understanding receptor function and developing drugs. Inverse agonists are used in therapeutic contexts where reducing the activity of a particular receptor is beneficial. For example, they have been explored for their potential in treating conditions associated with overactive receptors, such as anxiety disorders. The concept of inverse agonism highlights the dynamic nature of receptor signaling, where ligands can not only activate or block but also modulate the inherent activity of the receptor itself.