L73: HPA Axis & Adrenal (part II) Flashcards Preview

FHB - Endocrinology (by Richie) > L73: HPA Axis & Adrenal (part II) > Flashcards

Flashcards in L73: HPA Axis & Adrenal (part II) Deck (38)
1

What is the biologically active precursor of Aldosterone

11-DOC

2

What enzyme deactivates cortisol into cortisone?

11B-HSD2

3

What enzyme deactivates cortisol into cortisone, in mineralocorticoid target cells?

11B-HSD2.

The big idea here is that cortisol isn't supposed to act on mineralocorticoid target cells, but glucocorticoid target cells.

4

What enzyme reactivates cortisone to cortisol, in glucocorticoid target cells?

11B-HSD1

5

What drug inhibits 11B-HSD2, resulting in excess MR activation?

Carbenoxolone

6

What does licorice do?

Inhibits 11B-HSD2, thereby preventing the inactivation of cortisol to cortisone in MR target cells.

7

What does licorice (glycrrhetinic acid) do?

Inhibits 11B-HSD2, thereby preventing the inactivation of cortisol to cortisone in MR target cells.

8

What are the 3 layers of the adrenal cortex?

Zona glomerulosa
Zona fasciculata
Zona reticularis

"GFR"

9

What layer of the adrenal cortex makes mineralocorticoids (eg. Aldosterone)?

Zona glomerulosa

10

What layer of the adrenal cortex makes glucocorticoids (eg. cortisol)?

Zona fasciculata

11

What innervates the adrenal medulla?

Splanchnic nerve

12

High ACTH and no cortisol. This drives the synthesis of

norepinephrine

13

Only in the adrenal medulla, cortisol stimulates the conversion of

norepinephrine to epinephrine.

14

High ACTH and no cortisol. This drives the synthesis of

norepinephrine (normally Epi is the dominant one)

15

21a hydroxylase deficiency

Congenital Adrenal Hyperplasia

16

Hypotension
Hyperkalemia
High plasma renin
Masculinization
High ACTH

CAH

17

Hypertension
Hypokalemia
Masculinization
High ACTH

2nd most common cause of CAH:

CYP11B1: 11-hydroxylase deficiency

18

Hypertension
Hypokalemia
Masculinization
High ACTH

2nd most common cause of CAH:

CYP11B1, 11-hydroxylase deficiency

19

What is the metabolic byproduct of catecholamine catabolism by COMT and MAO, that is excreted in urine?

VMA (vanillylmandelic acid)

20

High urinary VMA may indicate

EPI/NE producing tumors

21

Pheochromocytoma

tumor originating from chromatin cell

22

Pheochromocytoma

tumor originating from chromatin cell.

23

Why is pheochromocytoma called a "10% tumor"?

10% are malignant
10% are bilateral
10% in children
10% familial
10% recur
10% associated with MEN
10% present with a stroke
10% extra-adrenal

24

ONLY IN THE ADRENAL MEDULLA, cortisol stimulates the conversion of

norepinephrine to epinephrine.

25

What do patients with 21a-hydroxylase or 11beta-hydroxylase deficiencies have in common?

Excess ACTH (lack of negative feedback, since no cortisol)

26

Steroidogenic regulatory protein

transfers cholesterol from the outer mitochondria to the inner mitochondria

27

Which of the following is regulated by ACTH?
A. StAR
B. Cholesterol ester hydrolase
C. ....add more
D. All of the above

D.

28

What zone of the adrenal gland does 11-hydroxylase (CYP11B1) live?

Z. fasciculata

29

What zone of the adrenal gland does CYP11B2 11-hydroxylase live?

Z. glomerulosa

30

Where in the adrenal gland is 17alpha-hydroxylase (CYP17)

Z. fasciculata and reticularis

31

Is 11B-HSD1 and 2 in the p450 family? Where does it live?

No. Kidney (type 2)

32

What's another name for aldosterone synthase?

CYP11B2

33

Where does CYP11B2 live?

Zona glomerulosa

34

Adrenal medulla is derived from

neural crest cells

35

Preganglionic neuron to adrenal neuron comes from

splanchnic nerve

36

Rate limiting step for dopamine synthesis?

Tyrosine hydroxylase

37

High ACTH but low cortisol. Will you lack:
A. Dopamine
B. NE
C. Epi

C. Epi

38

George has high BP that is unresponsive to BP lowering meds. What should you check for?

Look at VMA in urine. Think: Pheochromocytoma is unresponsive to B-blocker