Adrenal Disorders

Question 1

Precursor for steroid hormones

Answer 1

Cholesterol

Question 2

different types of corticosteroid?

Answer 2

mineralocorticoid, glucocorticoid, sex steroids
Made in the adrenal cortex

Question 3

effect of angiotensin II on adrenal glands?

Answer 3

activation of many metabolic enzymes leading to increased corticosteroid production

Question 4

aldosterone main actions?

Answer 4

controls blood pressure → increases sodium reabsorption and potassium excretion

Question 5

effect of ACTH on adrenal cortex?

Answer 5

activates many enzymes including 11-, 21-, 17-hydroxylase → more production of corticosteroids

Question 6

one lifestyle factor increasing ACTH production?

Answer 6

Stress (cortisol is a stress hormone)

Question 7

first steps of metabolic pathway for cholesterol?

Answer 7

cholesterol → pregnenolone → progesterone

Question 8

what is addison’s disease?

Answer 8

primary adrenal failure

mediated by autoimmune adrenal cortex destruction or tuberculosis of adrenal glands

Question 9

ACTH levels in Addison’s?

Answer 9

high → melanocyte stimulating hormone MSH high too

Question 10

Symptoms of addisons

Answer 10

hyperpigmentation and possible coexistent autoimmune vitiligo, low blood pressure, weakness, weight loss, nausea, diarrhoea/constipation, vomiting

Question 11

what is an adrenal crisis?

Answer 11

fever, syncope, convulsions, hypoglycaemia, hyponatraemia, severe vomiting and diarrhoea

Question 12

why hyperpigmentation?

Answer 12

ACTH and MSH come from the same precursor that is cleaved during formation (pro-opio-melanocortin POMC

Question 13

• biochemical consequences of adrenal failure?

Answer 13

hyponatraemia, (postural) hypotension, hyperkalaemia, low glucose (glucocorticoid deficiency), high ACTH

• blood → Na+ and K+9am cortisol (at peak so can observe too low), ACTH

Question 14

Tests for addisons

Answer 14

blood → Na+ and K+ . Sodium would be low and potassium high

9am cortisol (at peak so can observe too low), ACTH

Question 15

what is a synACTHen test?

Answer 15

inject synACTHen and observe cortisol before and after e.g. 9:00 and 9:30

should be higher in response

Question 16

treatment for primary adrenal failure?

Answer 16

replacement of cortisol and aldosterone

Question 17

• what is used to replace aldosterone and why?

Answer 17

fludrocortisone → longer half-life than aldosterone (has F group)

Question 18

What else can replace aldosterone

Answer 18

hydrocortisone and prednisolone

Question 19

most common cause of congenital adrenal hyperplasia?

Answer 19

21-hydroxylase deficiency → complete or partial
Complete deficiency means complete absence of aldosterone and cortisol,excess sex steroids

Question 20

• how long can you survive?

Answer 20

babies present within 1-3 weeks with a salt losing crisis

Question 21

possible consequence of excess testosterone?

Answer 21

girls may have ambiguous genitalia which is virilised by testosterone

Question 22

main problem in partial 21-hydroxylase deficiency?

Answer 22

hirsutism and virilisation in girls, precocious puberty in boys

(kind of enough cortisol and aldosterone, excess testosterone)

• not enough cortisol to inhibit ACTH → chronic adrenal overactivity

Question 23

why might adrenal hyperplasia arise?

Answer 23

not enough cortisol to inhibit ACTH → chronic adrenal overactivity

Question 24

consequence of 11-hydroxylase deficiency?

Answer 24

accumulation of 11-deoxycortisol/11-deoxycorticosterone

excess of sex steroids

Question 25

consequence of that? (11 hydroxylase deficiency)

Answer 25

11=deoxycorticosterone behaves like aldosterone → hypertension and hypokalaemia in excess

Question 26

consequence of 17-hydroxylase deficiency?

Answer 26

can’t produce cortisol or sex steroids, excess aldosterone and 11-deoxycorticosterone

Question 27

Cushings symptoms

Answer 27

fat pad, red striae, centripetal obesity, moon face, easy bruising and poor wound healing, thin skin
Hypertension and hypokalaemia

Question 28

what stops cortisol from activating aldosterone receptors under normal conditions?

Answer 28

11-beta-hydroxysteroid dehydrogenase (11-beta-HSD)
Done via turning it into inactive form of cortisone

Question 29

Causes of cushings

Answer 29

Too many steroids,pituitary disorder,ectopic ACTH from lung cancer

Question 30

Investigation for cushings

Answer 30

24hr urine collection, blood diurnal cortisol level, low dose dexamethasone suppression test
Cortisol measured at midnight as that’s the lowest point

Question 31

what is the dexamethasone suppression test?

Answer 31

artificial steroid taken 6 hourly for 48 hrs

healthy people suppress cortisol to 0, any cause of Cushing’s fails to suppress

measure basal 9am and end of LDDST

Question 32

functions of hyperadrenal disorder medications?

Answer 32

Enzyme inhibitors
Receptor blockers

Question 33

what are some inhibitors of steroid biosynthesis? how do they work?

Answer 33

Metyrapone-11 hydroxylase inhibitor (blocks formation of cortisol),used pre surgery/post radiotherapy cushings control,mean serum cortisol of 150-300. Can cause hirsuitism and hypertension

Ketoconazole-17 hydroxylase inhibitor. Used for cushings to control prior to surgery,can cause fatal liver damage

Osilodrostat-mainly 11 hydroxylase and 17 hydroxylase

Question 34

treatment of cushing’s?

Answer 34

depends on cause, some options are pituitary surgery and bilateral adrenalectomy (unilateral for adrenal mass)

Question 35

what is conn’s syndrome?

Answer 35

benign adrenal cortical tumour causing aldosterone excess
Hypertension,hypokalaemia,renin angiotensin system suppressed
Treat with aldosterone receptor antagonist spironolactone and eplerenone. Can cause gynaecomastia

Question 36

what are pheochromocytomas?

Answer 36

Tumours of adrenal medulla
Create an excess of catecholamines (adrenaline and noradrenaline)

Question 37

Pheochromocytomas

Answer 37

Hypertension in young people,sever episodic hypertension,high adrenaline can cause ventricular fibrillation and death

Question 38

Management of pheochromocytomas

Answer 38

Surgery needed
An aesthetic can precipitation hypertensive crisis

alpha blockade to prevent vasoconstriction, then possible beta blockade to prevent tachycardia