Table 1 Adrenergic receptors
From: Altered pharmacological effects of adrenergic agonists during hypothermia
|  | α-receptor | β-receptor | Dopamine-receptor |
|---|---|---|---|
Subgroups | α1, α2 | β1, β2, β3 | D1, D2, D3, D4, D5 |
Mechanism of action | G-protein coupled receptors | G-protein coupled receptors | G-protein coupled receptors |
Molecular effects | α1: Activation of PLC, IP3 mediated intracellular calcium increase α2: Decreased cAMP production | Increase of cAMP, protein phosphorylation (β1, β2, β3), intracellular calcium increase (β1) or decrease (β2) | D1, D5: Increase of cAMP D2, D3, D4: Decreased cAMP production |
Hemodynamic effect | α1: Vasoconstriction↑ α2: Mixed (vasoconstriction or vasodilation) | β1: Heart rate↑, contractility↑ β2: Vasodilation↑ | D1, D5: Vasodilation↑ D2, D3, D4:: Vasoconstriction↓ |
Dominant location | α1: Smooth muscle α2: Central nervous system | β1: Cardiac tissue β2: Smooth muscle β3: Adipose tissue | D1, D2, D3, D4, D5: Central nervous system |