Noradrenaline

Question 1

Source

Answer 1

Tyrosine==>L-dopa==>dopamine==>norepinephrine==> epinephrine

Question 2

Rate limiting step

Answer 2

Tyrosine hydroxylase

Question 3

Synthetic enzymes

Answer 3

Dopamine-b-hydroxylase modulates norepinephrine production

Phenylethanolamine-N-methyltransferase modulates conversion of NEN to epinephrine

Question 4

Breakdown enzymes

Answer 4

Monoamine oxidase (MAO-A) and Catechol-o-methyl transferase (COMT)

Question 5

Breakdown product

Answer 5

• 3-methoxy-4 hyudroxyphenylglycol (MHPG) and VMA- vanillyl mandelic acid
• MHPG is the major metabolite in CNS while VMA is major metabolite from peripheral nervous system/endocrine system

Question 6

Reuptake

Answer 6

• nroadrenaline reuptake channesls

- tricyclics and reboxetine inhibit this

Question 7

Function

Answer 7

-arousal, anxiety, mood regulation, autonomic mediation

Question 8

Receptors

Answer 8

• 2 major types: alpha and beta
• alpha is divided into alpha 1 and 2
• alpha 1 receptors are phospholipase C coupled and mostly postsynaptic
• alpha 2 receptors are Gi coupled and are mostly presynaptic autoreceptors
• Beta receptors are Gs coupled and predominate locus coeruleus- may regulate arousal
• Beta 1 receptors have high affinity to norepinephrine and Beta 2 receptors have high affinity to epinephrine

Question 9

Disorders

Answer 9

-levels low in depression and abnormal in panic/anxiety disorders