Alpha-1, beta-1, and beta-2 adrenergic receptors (α1, β1, β2-AR)

The alpha-1, beta-1, and beta-2 adrenergic receptors are a group of G protein-coupled receptors (GPCRs) that mediate the effects of the sympathetic nervous system in response to endogenous catecholamines like epinephrine and norepinephrine (StatPearls, 2023). Alpha-1 receptors are primarily located on vascular smooth muscle and mediate vasoconstriction, thereby increasing systemic vascular resistance and blood pressure (CV Pharmacology, 2023). Beta-1 receptors are predominantly found in the heart, where their activation increases heart rate and myocardial contractility, while Beta-2 receptors are located in the lungs and certain blood vessels, promoting bronchodilation and vasodilation (NIH, 2023). This specific combination of receptors is a key therapeutic target for non-selective beta-blockers with alpha-blocking activity, such as carvedilol and labetalol. These drugs are used to manage cardiovascular conditions like hypertension and heart failure by simultaneously reducing cardiac workload and promoting peripheral vasodilation (FDA, 2023).

Other names

AdrenoceptorsAdrenergic receptorsAlpha-1, beta-1, and beta-2 adrenoceptorsCombined alpha and beta adrenergic receptors

Competitive antagonism (e.g., carvedilol, labetalol) and agonism (e.g., epinephrine, norepinephrine).