Alpha-1 (Adrenergic) Receptors
8157
Summary
Alpha-1 adrenergic receptors are G-protein coupled receptors that make up the sympathetic response in the autonomic nervous system. When a ligand binds to the Alpha-1 receptor, it’s corresponding Gq protein will trigger a cascade of downstream messengers, including phospholipase C, IP3, and DAG. Since alpha-1 receptors are found on smooth muscle, activation of these receptors will lead to muscle contraction, such as vasoconstriction, pupil dilation, and bladder sphincter constriction.
Key Points
- Alpha-1 Receptors
- Signaling
- Use the Gq signaling pathway
- Outcomes
- Vasoconstriction
- Mydriasis (pupil dilation)
- Urinary sphincter contraction (less urine)
- Signaling