Pharm

Alpha Adrenergic Receptor

Alpha Adrenergic Receptor, Alpha 1 Adrenergic Receptor, Alpha 2 Adrenergic Receptor, Alpha Adrenergic Agonist, Alpha 1 Adrenergic Activity, Alpha 2 Adrenergic Activity

See Also

Effects
Alpha Receptor General

Vascular Smooth Muscle
1. Skin and skeletal Muscle vessel constriction
2. Splanchnic vessel constriction
Gastrointestinal
1. Myenteric Plexus Inhibition
Genitourinary
1. Pregnant Uterus contraction
2. Penis and seminal Vesicle ejaculation
Skin
1. Pilomotor smooth Muscle Contraction
2. Apocrine gland contraction
Metabolic
1. Gluconeogenesis
2. Glycogenolysis

Effects
Alpha 1 Receptors

Vascular Smooth Muscle postsynaptic Neurons
1. Vasoconstriction
Myocardium
1. Positive Inotrope
2. Negative Chronotrope
Eye
1. Radial Muscle Contraction
Gastrointestinal and Genitourinary
1. Sphincter (e.g. anus) contraction

Effects
Alpha 2 Receptors

Peripheral Alpha 2 Receptors
1. Vascular Smooth Muscle (mixed effect)
  1. Modulates large vessel tone
  2. Arteriolar and venous Vasoconstriction
  3. Opposes alpha 1 receptor Vasoconstriction
    1. Inhibits Norepinephrine release
    2. Decreases adrenergic activity
2. Gastrointestinal
  1. Smooth Muscle wall relaxation
3. Metabolic
  1. Fat Cell Lipolysis
Central Alpha 2 Receptors (CNS)
1. Inhibits Locus Ceruleus reflex arc
2. Peripheral vasodilatation

Medications
Alpha Adrenergics

Alpha Adrenergic Agonist (Alpha Adrenergic Receptor)
1. Alpha Non-Specific
  1. Epinephrine
  2. Norepinephrine
2. Alpha 1 Selective
  1. Phenylephrine
  2. Methoxamine
3. Alpha 2 Selective
  1. Clonidine (See Central Adrenergic Agonist)
  2. Alpha-methylnorepinephrine
Alpha Receptor Antagonist
1. Alpha Non-Specific
  1. Phentolamine
2. Alpha 1 Selective
  1. Prazosin (See Alpha Adrenergic Antagonist)
  2. Phenoxybenzamine
3. Alpha 2 Selective
  1. Yohimbine
  2. Tolazoline