Alpha-2 adrenergic receptor – Location, Actions, Agonist, Antagonists

Location:

• Prejunctional – adrenergic nerve endings
• Post junctional – brain, pancreatic B cells
• Extrajunctional – certain blood vessels, platelets

Actions:

• Inbition of neurotransmitter release
• Decreased central sympathetic outflow
• Decreased insulin synthesis
• Vasoconstriction
• Platelet aggregation

Agonist – Clonidine

Antagonist – Yohimbine, Rauwolscine

1. Clonidine
2. Alpha Methyl Noradrenaline
3. Methyldopa
4. Drug therapy for hypertension