Adrenergic Receptors and Their Predominant Physiological Effects
Adrenergic receptors, also known as adrenoceptors, are cell surface glycoproteins that recognize and selectively bind the catecholamines, norepinephrine and epinephrine to stimulate the nerves in your body’s sympathetic nervous system (SNS). Here is a list of cholinergic receptors and their major pharmacological effects:
Eye
- α1 (Iris radial muscle) – Pupillary dilation
- β2 (Ciliary muscle) – Relaxation for far vision
Heart
- β1, β2 (Sinoatrial, atrioventricular nodes) – Increased spontaneous depolarization
- β1, β2 (His-Purkinje system) – Increased conduction velocity
- β1, β2 (Atria, ventricles) – Increased contractility
Blood vessels
- α1, α2, β2 (Arteries, arterioles) – Constriction via α1, α2; dilation via β2
- α1, α2, β2 (Veins, venules) – Constriction via α1, α2; dilation via β2
Lungs
- β2 (Tracheal, bronchial muscle) – Relaxation of smooth muscle
- α1, β2 (Bronchial glands) – Decreased secretions
GI tract
- α1 (Salivary glands) – Decreased secretions
- α1, α2, β2 (Stomach) – Decreased motility; decreased secretions
- α1, β2 (Intestines) – Decreased motility
Urinary bladder
- β2 (Detrusor) – Relaxation, increased capacity
- α1 (Trigone, sphincter) – Contraction
Sex organs
- α1 – Ejaculation
Skeletal muscle
- β2 – Increased contractility; glycogenolysis
Liver
- α1, β2 – Increased glycogenolysis
Pancreas
- β2 – Increased insulin release
Fat cells
- β1, β2, β3 Lipolysis
Kidneys
- α1, β1 – Increased renin release
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