Lecture 9 (The Adrenergic System) Flashcards
alpha 1 stimulates what organs/tissues?
- arterioles (peripheral vascular skeletal muscle)
- eye (radial muscle)
- uterus
- intestines
- liver
- urinary
What affect does alpha 1 have on:
-arterioles (peripheral vascular skeletal muscle)
vasoconstriction
What affect does alpha 1 have on:
-eye (radial muscle)
contraction of radial muscle to dilate pupils
What affect does alpha 1 have on:
-uterus
contraction
What affect does alpha 1 have on:
-intestines
decreased motility
What affect does alpha 1 have on:
-liver
increased glycogenolysis
What affect does alpha 1 have on:
-urinary
contracts urinary sphincter
beta 1 stimulates what organs/tissues?
- kidney
- heart
What affect does beta 1 have on:
-kidney
renin release
What affect does beta 1 have on:
-heart
increase HR
increase contractility
beta 2 stimulates what organs/tissues?
- arterioles (peripheral vascular skeletal muscle)
- lung
- uterus
- intestine
- liver
- urinary
What affect does beta 2 have on:
-arterioles (peripheral vascular skeletal muscle)
vasodilation
What affect does beta 2 have on:
-lung
bronchodilation
What affect does beta 2 have on:
-uterus
relaxation
What affect does beta 2 have on:
-intestine
decreased motility
What affect does beta 2 have on:
-liver
increased glycogenolysis
What affect does beta 2 have on:
-urinary
relax bladder
How do you make a drug specific to a certain receptor?
ex. want to make it B1 specific therefore it would not stimulate B2
want to:
- increase potency at desired receptor (B1)
- decrease potency at undesired receptor (B2)
- if possible
- *cannot always do both
You can control selectivity with?
changing doses
*see slide 4
all adrenergic receptors are ____
GPCRs
alpha 1 = Galpha__
q
alpha 2 = Galpha__
i
Tissue locations for alpha 1?
- arterioles
- pupil
- liver
- GI smooth muscle
Cellular effects from alpha 1?
+PLCy
increase IP3, DAG
increase intracellular [Ca2+]
decrease K+ outflow
Results in:
Excitation
Tissue locations for alpha 2?
- presynaptic (autoreceptor)
- presynaptic inhibition
- platelets
- platelet aggregation
Cellular effects for alpha 2?
-AC
decrease cAMP
decrease intracellular [Ca2+]
increase K+ outflow
Results in:
Inhibition
B1 = Galpha_
s
B2 = Galpha_
s
B3 = Galpha_
s
Tissue locations for B1?
- heart
- GI smooth muscle
- kidney ? pretty sure
Cellular effects for B1?
+AC
increase cAMP
increase [Ca2+] stores in ER
Results in:
excitation
Tissue locations for B2?
- lungs
- muscle blood vessels
- liver
- GI smooth muscle
- skeletal muscle
Cellular effects for B2?
+AC
increase cAMP
Results in:
excitation
Tissue locations for B3?
adipose tissue
*lipolysis
Cellular effects for B3?
+AC
increase cAMP
Results in:
excitation
Describe the synapse for NA
- voltage gated Ca2+ channel is activated and creates an action potential
- this triggers NA to leave synaptic vesicle and head into the synaptic cleft and then into the post synaptic cell for receptors or come back onto the presynaptic cell for receptors
*see slide 7
What are the 3 ways to eliminate the signal from NA?
1) reuptake at synapse
2) COMT
3) MOA
COMT
catechol-o-methyl transferase
MOA
monoamine oxidase
What is the most important mechanism for the elimination of NA signal?
reuptake at synapse
Describe the mechanism of COMT
- a major reason that NA and A are not orally bioavailable
- this is a Phase 2 metabolism enzyme
Describe the mechanism of MOA
- this is a phase 1 metabolism enzyme
- this is NOT a CYP enzyme
What are MOPEG and VMA?
- the main metabolites of NA and A
- they are conjugated before excretion
Where is MAO found?
in mitochondria of presynaptic terminal