Gosset Molecular Classification
G Protein-Coupled Receptor (GPCR), Receptor, Class A GPCR
Other Names
alpha1-adrenergic receptor, alpha1 adrenoreceptor, α1 adrenoreceptor, Adrenergic Receptor Alpha 1
Disease Roles
Alpha1 Adrenergic Receptor Overview
The alpha1 adrenergic receptor (α1-AR) is a G protein-coupled receptor that mediates physiological responses to sympathetic nervous system activation. Activated by norepinephrine and epinephrine, it primarily couples to Gq/11 proteins, increasing intracellular calcium. It plays a key role in smooth muscle contraction, vasoconstriction, and modulation of CNS activity. There are three subtypes: α1A, α1B, and α1D. Dysregulation has been implicated in cardiovascular function and other clinical disorders.
Mechanism of Action
Agonist binding leads to Gq/11 protein activation, stimulating phospholipase C (PLC) and increasing intracellular calcium levels. Antagonists block the receptor, preventing catecholamine binding and downstream signaling.
Biological Functions
Signal transduction
Smooth muscle contraction
Vasoconstriction
Neurotransmission modulation
Disease Associations
Cardiovascular disease
Urinary retention
Urinary incontinence
Central nervous system disorders
Safety Considerations
- Orthostatic hypotension
- Side effects of adrenergic receptor blockade (e.g., dizziness, nasal congestion)
- Potential for drug interactions due to widespread expression and effects
Interacting Drugs
Norepinephrine