Endo - Adrenal Disorders

Question 1

What is a steroid?

Answer 1

a chemical that comes from cholesterol

Question 2

What enzymes are needed for the synthesis of aldosterone?

Answer 2

angiotensin II activates:
→ side chain cleavage
→ 3 hydroxysteroid dehydrogenase
→ 21 hydroxylase
→ 11 hydroxylase
→ 18 hydroxylase

Question 3

What enzymes are needed for the synthesis of cortisol?

Answer 3

ACTH activates:
→ side chain cleavage
→ 3 hydroxysteroid dehydrogenase
→ 17 hydroxylase
→ 21 hydroxylase
→ 11 hydroxylase

Question 4

What are the actions of aldosterone?

Answer 4

→ controls BP
→ controls sodium
→ lowers potassium

Question 5

When is the best time to measure cortisol?

Answer 5

early in the morning

Question 6

What is Addison’s disease?

Answer 6

primary adrenal failure
→ adrenal glands don’t produce sufficient hormones
→ pituitary produces too much ACTH + MSH

Question 7

What is the world’s no.1 common cause of Addison’s?

Answer 7

tuberculosis of adrenal glands

Question 8

What are the symptoms of Addison’s disease?

Answer 8

→ hyperpigmentation
→ hypotension
→ weakness
→ weight loss
→ vitiligo
→ gastrointestinal issues (nausea, diarrhoea, vomiting, constipation, ab pain)

Question 9

Why do Addison’s disease patients have hyperpigmentation?

Answer 9

→ POMC is precursor for ACTH

→ when cleaved to produce ACTH, MSH is also produced

Question 10

What are the 2 main mechanisms that cause adrenal failure generally?

Answer 10

→ enzymes in steroid synthetic pathway not working

→ adrenal glands destroyed

Question 11

What is the most common cause of Addison’s Disease in the UK?

Answer 11

autoimmune Addison’s disease

Question 12

What are 3 causes of adrenocortical failure?

Answer 12

→ TB Addison’s disease
→ autoimmune Addison’s disease
→ congenital adrenal hyperplasia

Question 13

What are clinical consequences of adrenocortical failure?

Answer 13

→ fall in BP
→ loss of salt (sodium) in urine
→ increased plasma potassium
→ fall in glucose due to glucocorticoid deficiency

Question 14

How can you test for Addison’s?

Answer 14

→ 9 am cortisol = low
→ ACTH = high
→ short synACTHen test (give 250 ug synacthen IM + measure cortical response)

Question 15

Why can’t you treat Addison’s with pure aldosterone?

Answer 15

→ half life of aldosterone too short for safe once daily administration
→ has to be done through IV

Question 16

What can you treat Addison’s disease with for aldosterone replacement?

Answer 16

fludrocortisone
→ aldosterone + fluorine
→ does not exist naturally
→ non-biodegradable

Question 17

Why can’t you treat Addison’s with pure cortisol?

Answer 17

→ too short of a high life
→ too short for daily administration - has to be given thrice but causes late peaks of cortisol
→ late peaks in cortisol are harmful

Question 18

Why can you treat Addison’s with for cortisol replacement?

Answer 18

hydrocortisone
→ longer half life
→ more potent than cortisol
→ 2.3 x binding affinity
prednisolone
→ longer half life (more accurate for cortisol diurnal rhythm)
→ more potent than cortisol
→ 2.3 x binding affinity

Question 19

What is a major cause of congenital adrenal hyperplasia?

Answer 19

21-hydroxylase deficiency

→ can be complete or partial

Question 20

What hormones are deficient in congenital adrenal hyperplasia?

Answer 20

aldosterone + cortisol

Question 21

How long can a baby survive with complete 21 hydroxylase deficiency?

Answer 21

less than 24 hrs

Question 22

Which hormones are in excess in 21 hydroxylase deficiency?

Answer 22

sex steroid + testosterone

Question 23

How will the baby present with 21 hydroxylase deficiency?

Answer 23

→ salt-losing Addisonian crisis (the placenta would’ve been feeding it nutrients)
→ girls may have ambiguous genitalia (excess of sex steroids causes virilisation of genitlia)

Question 24

At what age do patients with partial 21 hydroxylase deficiency present?

Answer 24

any age after survival

Question 25

What are the symptoms of partial 21 hydroxylase deficiency?

Answer 25

→ usually has enough cortisol + aldosterone to get by
→ excess sex steroids cause hirsutism + virilisation in girls
→ causes precocious puberty in boys

Question 26

What hormones are deficient in 11 hydroxylase deficiency?

Answer 26

cortisol + aldosterone

Question 27

Which hormones are in excess in 11 hydroxylase deficiency?

Answer 27

→ 11-deoxycorticosterone

→ sex steroids + testosterone

Question 28

What are the consequences of 11-hydroxylase deficiency?

Answer 28

→ virilisation
→ hypertension
→ low potassium

Question 29

What hormones are deficient in 17-hydroxylase deficiency?

Answer 29

→ cortisol

→ sex steroids

Question 30

Which hormones are in excess in 17 hydroxylase deficiency?

Answer 30

→ 11-deoxycorticosterone

→ aldosterone (mineralcorticoids)

Question 31

What are the consequences of 17-hydroxylase deficiency?

Answer 31

→ hypertension
→ low potassium
→ sex steroid deficiency
→ glucocorticoid deficiency