Adrenergic receptors and actions

Adrenergic receptors and actions
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This is a short summary of Adrenergic receptors and their actions throughout the body
ADDITIONAL TAGS:
Adrenergic Receptors
(G-protein subunits)
Second Messenger(s)
Locations of Receptors
and Actions
α1
(Gq)
↑ IP3 → ↑ Ca2+
↑ DAG → ↑ PKC
Smooth muscles
Blood vessels: vasoconstriction
Bladder neck: sphincter contract
GI: sphincter contraction
Iris dilator muscle: mydriasis
α2
(Gi)
↓ cAMP → ↓ Ca2+
Ciliary body: ↓ aqueous humor secretion
Pancreas: ↓ insulin secretion
Platelets: induces platelet aggregation
Prejunctional nerve: ↓ norepi release
β1
(Gs)
↑ cAMP → ↑ Ca2+
Heart: ↑ heart rate, conduction velocity, and force of contraction
Kidney: ↑ renin release
β2
(Gs)
Mixed effect, mainly
↑ cAMP → ↑ Ca2+
Liver: ↑ glycogenolysis
Pancreas: ↑ insulin secretion
Smooth muscles
Bladder: relaxation
Blood vessels: vasodilation
Bronchioles: bronchodilation
Uterus: uterine relaxation
Abbreviations: cAMP, cyclic adenosine monophosphate; DAG, diacylglycerol; Gi, G protein inhibitory; Gq, G protein q polypeptide; Gs, G protein stimulatory; IP3, inositol trisphosphate; PKC, protein kinase C.