OCB03-2009 NORADRENALINE

Question 1

What type of function do α-adrenergic receptors have?

Answer 1

Excitatory or inhibitory

Question 2

What type of function do β-adrenergic receptors have?

Answer 2

Excitatory

Question 3

What CNS functions is NA important in?

Answer 3

Arousal

Central blood pressure regulation

Mood control

Question 4

What are the two major nuclei containing noradrenergic neurons?

Answer 4

Locus coeruleus

Caudal raphe nuclei

Question 5

Where is the locus coeruleus found?

Answer 5

Midbrain

Question 6

Where are the caudal raphe nuclei found?

Answer 6

Near brainstem

Question 7

Where do noradrenergic neurons from the locus coeruleus project to?

Answer 7

Frontal cortex

Thalamus

Hypothalamus

Limbic system

Cerebellum

Question 8

Where do noradrenergic neurons from the caudal raphe nuclei project to?

Answer 8

Ascend to amygdala

Descend to spinal cord

Question 9

How is NA formed?

Answer 9

Dopamine –> NA by dopamine-β-hydroxylase in vesicles

Question 10

Where is dopamine-β-hydroxylase found?

Answer 10

In vesicles

Question 11

What is the pathway of NA degradation in neurons?

Answer 11

NA –> dihydroxymandelic acid by MAOa

Dihydroxymandelic acid –> methoxyhydroxymandelic acid by COMT

Question 12

What is the pathway of NA degradation in glial cells?

Answer 12

NA –> normetanephrine by COMT

Normetanephrine –> methoxyhydroxymandelic acid by MAOa

Question 13

What can be measured to determine NA activity in the CNS?

Answer 13

Measure methoxyhydroxymandelic acid in urine

Question 14

What does VMA mean?

Answer 14

Methoxyhydroxymandelic acid (vanillylmandelic acid)

Question 15

How is NA removed from the synapse?

Answer 15

NET into neurons

ENT into glial cells

Question 16

What does NET mean?

Answer 16

Norepinephrine transporter

Question 17

What is the function of the presynaptic α2-receptors?

Answer 17

Inhibits NT release and inhibits voltage-gated Ca channels

Question 18

What happens when α1-receptors are activated?

Answer 18

Gq

PLC activated to increase IP3 and DAG

Increases intracellular Ca++

Question 19

What happens when postsynaptic α2-receptors are activated?

Answer 19

Gi

Adenylyl cyclase inhibited and K channel open and voltage-gated Ca channels close

K+ efflux = re/hyperpolarisation

Question 20

What G protein are the β-adrenoceptors coupled to?

Answer 20

Gs

Question 21

What receptors does isoprenaline act on?

Answer 21

Agonist for β1/2

Question 22

What is isoprenaline used to treat?

Answer 22

Asthma

Question 23

What receptors does dobutamine act on?

Answer 23

Agonist for β1

Question 24

What is dobutamine used to treat?

Answer 24

Cardiogenic shock

Question 25

What receptors does salbutamol act on?

Answer 25

Agonist for β2

Question 26

What types of drugs are used to treat asthma?

Answer 26

β2 agonists

Question 27

What receptors does phenylephrine act on?

Answer 27

Agonist for α1

Question 28

What is phenylephrine used to treat?

Answer 28

Nasal congestion

Question 29

What receptors does clonidine act on?

Answer 29

Agonist for α2

Question 30

What is clonodine used to treat?

Answer 30

Hypertension Migraine High intraocular pressure Menopause flushing

Question 31

What receptors does phentolamine act on?

Answer 31

Antagonist of α1/2

Question 32

What receptors does prazocin act on?

Answer 32

Antagonist of α1

Question 33

What is prazocin used to treat?

Answer 33

Hypertension

Question 34

What receptors does propanolol act on?

Answer 34

Antagonist for β1/2

Question 35

What is propanolol used to treat?

Answer 35

Angina Hypertension Dysrhythmias Anxiety Tremor

Question 36

What receptors does metoprolol act on?

Answer 36

Antagonist of β1

Question 37

What is metoprolol used to treat?

Answer 37

Angina Hypertension Dysrhythmias

Question 38

How does amphetamine or methylphenidate affect NA transmission and what is the result of this?

Answer 38

Displace NA from vesicles and inhibit MAO to increase NA release (leakage) Addictive, stimulant; psychoses Calming in ADHD Narcolepsy Appetite suppressant

Question 39

How does cocaine affect NA transmission and what is the result of this?

Answer 39

Inhibits NET (main action on DAT) Addictive, stimulant

Question 40

How do tricyclic antidepressants/NSRIs/SNRIs affect NA transmission?

Answer 40

Inhibit NET

Question 41

What is ephedrine used to treat?

Answer 41

Nasal decongestant (increases NA release in CNS)

Question 42

How do MAO inhibitors affect NA transmission? What can they be used to treat?

Answer 42

Decreased NA metabolism Treat depression