Alpha-2 adrenergic receptor

Alpha-2 adrenergic receptor (α2 adrenergic receptor), also known as ADRA2, is a class of G protein-coupled receptors that are targets of the catecholamines, particularly norepinephrine and epinephrine.

Function

The alpha-2 adrenergic receptor has several general functions in common with other adrenergic receptors, but also has specific effects. It inhibits the release of norepinephrine, acts as a feedback inhibitor, and reduces the release of glutamate and acetylcholine. It also plays a role in pain modulation, sedation, and hypothermia.

Subtypes

There are three highly homologous subtypes of alpha-2 adrenergic receptor: α2A, α2B, and α2C. These subtypes are found in different locations in the body and have different functions. For example, the α2A subtype is found in the brain and is thought to mediate the symptomatic effects of hypertension, while the α2B subtype is found in the blood vessels and mediates vasoconstriction.

Clinical significance

Alpha-2 adrenergic receptors have been implicated in a variety of disorders, including hypertension, depression, anxiety disorders, and pain. Drugs that act on these receptors can have therapeutic effects in these conditions. For example, clonidine and dexmedetomidine are alpha-2 adrenergic receptor agonists that are used to treat hypertension and provide sedation, respectively.

See also

• Adrenergic receptor
• G protein-coupled receptor
• Norepinephrine
• Epinephrine

References

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