Norepinephrine (NE)
Epinephrine(E)
Receptors
By
Gül Günay
Sevilay Akköse
Gözde Çolak
Norepinephrine, epinephrine, are
in the class of catecholamines
and they bind to adrenergic
receptors.
Norepinephrine (noradrenalin)
¾ Released by the sympathetic
postganglionic nerve endings
5
HO
HO
6
1
4
3
2
CHOH
CH2
NH2
Epinephrine (adrenalin)
¾ A methyl derivative of norepinephrine. It
is
primarily an emergency hormone
produced by the adrenal medulla.
5
HO
HO
6
1
4
3
2
CHOH
CH2
NHCH3
Sympathetic
Division
Both NE and E affect
sympathetic nerves
-NE is neurotransmitter
-E is hormone
z
z
z
Increase heart rate and
strength of contraction
Mobilize glucose from liver
Inhibit digestive activity
Synthesis of E and NE
Adrenergic Receptors
¾
¾
Seven-pass
transmembrane
proteins that are
coupled to G proteins
There are multiple
receptor types which
are differentially
expressed in different
tissues and cells.
¾ Two main families of adrenergic receptors
z
z
Alpha (α)
Beta (ß)
NE,E
α
ß
E
Adrenergic
Receptor
Subtypes
Main Type of Adrenergic Receptors
Receptor
Agonists
Second Messenger
G protein
alpha1 (α1)
E>NE
IP3/Ca2+; DAG
Gq
alpha2 (α2)
NE>E
↓ cyclic AMP
Gi
beta1 (β1)
E=NE
↑ cyclic AMP
Gs
beta2 (β2)
E>>NE
↑ cyclic AMP
Gs
α1-receptor
α2-receptor
(IP3, DAG)
(↓ cAMP)
Process
β1receptor
(↑ cAMP)
β2-receptor
(↑ cAMP)
Carbohydrate ↑ liver
No effect
metabolism
glycogenolysis
No effect
↑ liver/muscle
glycogenolysis;
↑ liver gluconeogenesis;
↓ glycogenesis
Fat
metabolism
No effect
↓ lipolysis
↑ lipolysis
No effect
Hormone
secretion
No effect
↓ insulin
secretion
No effect
↑ insulin and glucagon
secretion
References:
¾
¾
¾
¾
¾
¾
¾
http://www.bio-logicsolutions.com/neurolog.htm
http://www.neuro.wustl.edu/neuromuscular/lab/catechol.
htm#ne
http://arbl.cvmbs.colostate.edu/hbooks/pathphys/endocri
ne/adrenal/medhormones.html
http://www.blackwellpublishing.com/matthews/neurotran
s.html
http://www.blackwellpublishing.com/matthews/neurotran
s.html
http://www.creighton.edu/~tpisarri/Powerpoints/Lecture1
1.ppt#339,25,Adrenergic Receptors
http://www.sosu.edu/faculty/mturnage/Fall%2003%20fol
ders /