Both NE and E increase contractility via beta-1
Vasodilation in skeletal muscle and liver (beta-2 receptor)
--> Overall vasodilation
Reflex bradycardia insufficient
Overall vasocontriction (alpha-1)
Reflex bradycardia sufficent to dominate
Norepinephrine = NE
Epinephrine = E
NE and E both increase HR and contractility in isolated heart, via beta-1 receptors.
Also see ANS innervation of the heart
Epinephrine causes vasodilation in skeletal muscles and liver via beta-2 receptors
--> This vasodilation overwhelms vasoconstriction caused by E elsewhere
--> PVR decrease (not increase)
[BL8:p245] Low doses of epinephrine cause muscle vasodilation, but high doses cause muscle constriction
Norepipherine causes vasoconstriction in almost all organs via alpha-1 receptors.