Alpha-1 adrenergic receptor (nasal blood vessel) (α1-AR)

Alpha-adrenergic receptors on nasal blood vessel smooth muscle, especially the alpha-1 subtype, mediate vasoconstriction when activated by endogenous catecholamines or sympathomimetic drugs. This action reduces nasal blood flow, resulting in decreased mucosal edema/congestion and relief of symptoms in conditions like allergic or infectious rhinitis. Alpha-1 receptors are predominantly postjunctional, while alpha-2 receptors are found postsynaptically and presynaptically (inhibiting norepinephrine release). Therapeutic alpha-1 agonists are used as nasal decongestants, but overuse may cause adverse effects such as rebound congestion and systemic cardiovascular effects.

Other names

Alpha-adrenergic receptoralpha-1 adrenoceptoralpha-adrenoceptorα1-adrenoceptornasal α-adrenergic receptor

Agonists bind to the receptor, leading to smooth muscle contraction (vasoconstriction) via intracellular signaling pathways (e.g., Gq protein, increased IP₃) Reduces nasal mucosal blood flow, resulting in tissue shrinkage and relief of congestion Some alpha-2 agonists also inhibit norepinephrine release (presynaptic)