Adrenergic receptor (venous smooth muscle) (null)

Venous smooth muscle adrenergic receptors are G protein-coupled receptors located on the smooth muscle cells of venous blood vessels, particularly mediating sympathetic nervous system signals[1][2]. They are represented primarily by alpha-1 (causing vasoconstriction upon activation), alpha-2 (whose effects vary depending on location—vasoconstriction peripherally but presynaptic inhibition leading to vasodilation systemically), and beta-2 (causing vasodilation)[1][2]. These receptors are targets for a variety of cardiovascular drugs that alter venous tone to influence systemic blood pressure and venous return[1][4].

Other names

Alpha-adrenergic receptor (alpha-1 adrenergic receptor, alpha-2 adrenergic receptor)Beta-adrenergic receptor (beta-2 adrenergic receptor)

Alpha-1 antagonist: blocks vasoconstriction, promotes vasodilation and lowers blood pressure; Alpha-1 agonist: induces vasoconstriction, increases blood pressure; Alpha-2 agonist: presynaptic inhibition of sympathetic tone (vasodilation dominates), but can cause post-synaptic vasoconstriction in blood vessels; Beta-2 agonist: mediates smooth muscle relaxation and vasodilation, mainly via cAMP signaling