Adrenal Pathway Dysfunction

Question 1

What are the 3 corticosteroids?

Answer 1

Mineralocorticoids(aldosterone)
Glucocorticoids (cortisol)
Sex steroids (androgens and oestrogens)

Question 2

What enzymes does angiotensin II turn on? What is synthesised as a result?

Answer 2

3, 11, 21, 18 hydroxylase= aldosterone synthesis

Question 3

What are the main actions of aldosterone?

Answer 3

Controls BP, sodium, lowers potassium

Question 4

What enzymes does ACTH turn on? What is synthesised as a result?

Answer 4

3, 11, 21, 17 hydroxylase= cortisol synthesis

Question 5

How is cortisol released?

Answer 5

Diurnal rhythmn- peaks in the morning (8:30 am)

Question 6

What is Addison’s disease?

Answer 6

Autoimmune destruction of adrenal cortex or TB of adrenal glands

Question 7

How does Addison’s disease present?

Answer 7

Higher pigmentation
Vitiligo (in mouth)
Low BP (no cortisol or aldosterone)
Extreme fatigue (low blood glucose due to loss of glucocorticoids) 
Hyponatraemia
Hyperkalaemia

Question 8

What are causes of adrenocortical failure?

Answer 8

Adrenal glands destroyed (Tb or autoimmune Addison’s)

Enzymes in steroid synthesis pathway not present (congenital adrenal hyperplasia)

Question 9

Whats the most common cause of Addison’s? and in the UK?

Answer 9

TB- not in UK, here autoimmune is more common

Question 10

What is the precursor to ACTH and MSH?

Answer 10

Pro opio melanocortin

Question 11

How is Addison’s diagnosed?

Answer 11

Cortisol

Question 12

What medication is given for Addison’s?

Answer 12

Fludrocortisone once daily to replace aldosterone
Hydrocortisone has too short a half life for once daily, can give 3 times daily
Prednisolone can be given as it has the right half life for a day

Question 13

What is congenital adrenal hyperplasia?

Answer 13

Commonest cause is deficiency of 21 hydroxylase (missing gene), means you cannot synthesise cortisol or aldosterone

Question 14

How long can you survive with congenital adrenal hyperplasia? How is it treated?

Answer 14

Only for a few hrs after you are born

Same treatment as Addison’s

Question 15

What are knock on effects of congenital adrenal hyperplasia? How is this visible?

Answer 15

Excess synthesis of sex steroids (testosterone) before birth

In a girl they have ambiguous genitals, boys theres no visible sign

Question 16

What hormones are completely missing in babies with congenital adrenal hyperplasia?

Answer 16

Cortisol and aldosterone

Question 17

How does congenital adrenal hyperplasia present?

Answer 17

Neonate salt losing crisis

Question 18

What happens if someone has a partial 21 hydroxylase deficiency? What age do they present and with what?

Answer 18

Lower levels of cortisol and aldosterone
Higher levels of testosterone
Present as children- precocious puberty in boys, hirtuism in girls

Question 19

What happens in 11 hydroxylase deficiency? What do they present with?

Answer 19

Low cortisol and aldosterone
High sex steroids and 11 deoxycortisone
Virilisation, hypertension (!! even when cortisol is low!!), low potassium

Question 20

What happens in 17 hydroxylase deficiency? What do they present with?

Answer 20

No testosterone
No cortisol
Excess 11 deoxycortisone
High BP, low K, no puberty, low glucose (glucocorticoid deficiency)