Where are alpha 1 receptors located
Vascular smooth muscle
Pupil dilator muscle
GIT
Where are alpha 2 receptors located
Nerve terminals
Vascular smooth muscle
Platelets
Where are beta 1 receptors located
Heart
Kidneys
GIT
Where are beta 2 receptors located
Lungs
Liver
Vascular Smooth muscle
Where are beta 3 receptors located
Adipocytes
Activation of alpha 1 receptors causes
Vasoconstriction
GIT relaxation
Activation of alpha 2 receptors causes
Pre-synaptic inhibition
Vasoconstriction
Platelet aggregation
Activation of beta 1 receptors causes
Increase contractility/ionotropy
Increase renin secretion
Relaxation
Activation of beta 2 receptors causes
Smooth muscle relaxation- bronchodilation
Vasodilation
Activate Glycogenolysis
Activation of beta 3 receptors causes
Activate lipolysis
Alpha 1 agonist
Phenylephrine
Alpha 1 antagonist
Phentolamine
Labetalol
Alpha 2 agonist
Clonidine
Alpha 2 antagonist
Phentolamine
Prazosin
Beta 1 agonist
Isoprenaline
Dobutamine
Beta 1 antagonist
Atenalol
Propranolol
Labetalol
Beta 2 agonist
Isoprenaline
Salbutamol
Beta 2 antagonist
Propranolol
Mechanism of each adrenorecptor
a1- Gq (PLC- increase Ca) a2-Gi (decrease cAMP- decrease NA) B1-Gs (increase cAMP) B2-Gs B3- Gs