Gosset Molecular Classification
G protein-coupled receptor, GPCR, Receptor
Other Names
Alpha1-adrenergic receptor, α1-adrenergic receptor, Alpha-1 adrenergic receptor
Disease Roles
Adrenergic Alpha1 Receptor Overview
The adrenergic alpha1 receptor (α1-AR) is a G protein-coupled receptor that mediates various physiological responses, most notably smooth muscle contraction and vasoconstriction. It is primarily activated by norepinephrine and epinephrine. There are three subtypes: α1A, α1B, and α1D, each with distinct tissue distributions and functions. Activation leads to stimulation of phospholipase C (PLC) via Gq/11 proteins, resulting in increased intracellular calcium and activation of protein kinase C. Alpha‐blockers targeting these receptors are used therapeutically for hypertension and benign prostatic hyperplasia.
Mechanism of Action
Gq/11 → PLC → IP3/DAG → ↑Ca²⁺/PKC, leading to smooth muscle contraction and other cellular effects.
Biological Functions
Signal transduction
Smooth muscle contraction
Vasoconstriction
Neurotransmission
Regulation of blood pressure
Cardiac contractility regulation
Ejaculation
Pupil dilation
Cell growth
Disease Associations
Hypertension
Benign prostatic hyperplasia
Cardiovascular diseases
Autonomic dysfunction
Safety Considerations
- Hypotension (due to excessive vasodilation)
- Dizziness
- Nasal congestion
Interacting Drugs
Norepinephrine
Epinephrine
Prazosin