Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Endo/Repro Exam 1 > Adrenal Catecholamines > Flashcards

Adrenal Catecholamines Flashcards

1
Q

What stain turns chromaffin cells yellow?

A

Chromium treatment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are chromaffin cells thought of in terms of pre or post ganglionic nerves?

A

Think of them as post-ganglionic sympathetic neurons considering their contents

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What do chromaffin granules contain?

A 
Chromogranin A (tumor marker)
Chromogranin B (tumor marker)
ATP
Neuropeptide Y
Enkephalins
Adrenomedullin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How are catecholamines concentrated?

A

By 4:1 binding with an ATP molecule (proton pumps them in)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the vesicular proton pump needed for?

A

Catecholamine concentration in chromaffin granules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is Adrenomedullin?

A

It is a marker for catecholamine release; increased would mean pheochromocytoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the pathway for formation of the catecholamines?

A

Phenylalanine-> Tyrosine-> Dopa-> Dopamine-> Norepinephrine-> Epinephrine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What step does the catecholamine synthesis usually begin?

A

Tyrosine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Rate limiting step in normal catecholamine synthesis?

A

Tyrosine to Dopa Tyrosine hydroxylase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What enzyme is needed for phenylalanine to tyrosine formation?

A

Phenylalanine hydroxylase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What enzyme is needed for tyrosine to dopa formation?

A

Tyrosine hydroxylase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What enzyme is needed for dopa to dopamine formation?

A

L-Aromatic amino acid decarboxylase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What enzyme is needed for dopamine to norepinephrine formation?

A

Dopamine-Beta-hydroxylase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What enzyme is needed for norepinephrine to epinephrine formation?

A

PNMT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the rate limiting step in pheochromocytoma patients?

A

Norepinephrine to epinephrine formation (PNMT)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What controls the action of PNMT?

A

Glucocorticoid stimulation

17
Q

Normal persons epinephrine to norepinephrine ratio?

A

4:1

18
Q

Pheochromocytoma patient epinephrine to norepinephrine?

A

1:5

19
Q

Where is the only place that epinephrine is synthesized?

A

Adrenal medulla

20
Q

What inhibits tyrosine hydroxylase?

A

Alpha-methyl tyrosine

21
Q

What inhibits vesicular monoamine transport?

A

Cocaine
Guanethidine
Selective norepinephrine reuptake inhibitors
Tricyclic antidepressants

22
Q

What effect do monoamine oxidase inhibitors have?

A

Inhibit the breakdown of catecholamines

23
Q

What effect do COMT inhibitors have?

A

Inhibit breakdown of catecholamines

24
Q

What two enzymes are needed for breakdown of catecholamines?

A

COMT

MAO

25
Q

What do you use alpha-methyl tyrosine to treat?

A

Pheochromocytoma inoperable one

26
Q

What are the side effects of alpha-methyl tyrosine?

A

Cystalluria (renal damage)
Sleepiness
Parkinson’s syndrome (decreased dopamine)

27
Q

What are the two breakdown pathways of norepinephrine?

A

Norepinephrine to Normetanephrine via COMT Normetanephrine to Vanillylmandelic acid via MAO

Norepinephrine to Dihydroxymandelic acid via MAO Dihydroxymandelic acid to Vanillylmandelic acid via COMT

28
Q

What are the two breakdown pathways of epinephrine?

A

Epinephrine to Metanephrine via COMT Metanephrine to Vanillylmandelic acid via MAO

Epinephrine to Dihydroxymandelic acid via MAO Dihydroxymandelic acid to Vanillylmandelic acid via COMT

29
Q

What test has high specificity for Pheochromocytoma?

A

Plasma Metanephrine levels

30
Q

Why are metanephrine levels tested and not Normetanephrine for pheochromocytoma?

A

Because only the adrenal medulla forms epinephrine and a pheochromocytoma acts as that; the periphery can increase norepinephrine levels

31
Q

What test has the greatest sensitivity to pheochromocytoma?

A

24 hour urine measurements of epinephrine, norepinephrine and VMA

32
Q

What is given in imaging studies to locate the pheochromocytoma tumor?

A

Meta-iodobenzylguanidine

33
Q

How is meta-iodobenzylguanidine uptaken?

A

Via neuronal uptake

34
Q

What has a higher sensitivity and specificity but is often only used in PET scanners?

A

F DOPA

35
Q

Where is meta-iodobenzylguanidine uptaken?

A

Pheochromocytoma

Moderate in liver, salivary glands, urine

36
Q

What is the treatment of symptomatic pheochromocytoma?

A

Alpha-1-antagonist Prazosin + Beta blocker in preparation for surgery

37
Q

What is the mechanistic treatment of pheochromocytoma?

A

Alpha-methyl tyrosine or Beta blocker + phenoxybenzamine (non-selective alpha blocker) or surgery

Endo/Repro Exam 1 (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions