Adrenal Gland Flashcards
Where is cortisol produced?
Zona Fasciculata
Zona Reticularis
Where is Aldosterone produced?
Zona Glomerulosa
Where are androgens produced?
Zona Reticularis
What are 4 metabolic effects of Glucocorticoids?
- increase gluconeogenesis
- release amino acids through muscle catabolism
- inhibit peripheral glucose uptake
- stimulate lipolysis
What is the role of 11beta-hydroxysteroid dehydrogenase type 2?
converts cortisol –> cortisone which has less affinity for aldosterone receptor preventing overstimulation
[type 1: cortisone –> cortisol]
Which synthetic corticosteroid is used therapeutically as a mineralocorticoid?
Fludrocortisone
What is the difference between Primary and Secondary Adrenocortical Insufficiency?
Primary- decreased cortisol AND aldosterone (destruction of adrenal gland); elevated ACTH
Secondary- decreased cortisol only (issue with pituitary or hypothalamus); decreased ACTH
When will hyperpigmentation be seen?
due to increased ACTH levels- Primary Adrenal Insufficiency
What is cosyntropin?
Synthetic derivative of ACTH used to diagnose suspected adrenal insufficiency
What is the main synthetic glucocorticoid used to treat primary adrenal insufficiency? Which one is used in emergency treatment of severe stress/trauma?
- Hydrocortisone is gold standard
- Dexamethasone used in emergency situations (30x stronger) [also used if no previous dx of adrenal insufficiency to monitor endogenous cortisol production]
How is Cushing’s Syndrome diagnosed?
overnight dexamethasone suppression test
should see low levels cortisol the next morning- if high –> Cushings
What is the Metyrapone test?
Metyrapone is selective inhibitor of 11beta-hydroxlase (11-deoxycortisol –> cortisol) and used to test pituitary production of ACTH (should increase)
What are 4 agents used to treat Cushing’s Syndrome and their mechanism of action?
- Aminoglutethimide- blocks cholesterol –> pregnenolone
- Ketoconazole- antifungal azole; inhibits adrenal/gonadal steroid synthesis
- Mitotane- cytotoxic to adrenal cortex (bad SEs)
- Mifepristone- glucocorticoid receptor antagonist
What should be on the differential if a patient has hypertension with hypokalemia?
Primary Aldosteronism
What is an agent used for the treatment of Primary Aldosteronism?
Spironolactone / Eplerenone
What is the most common form of Congenital Adrenal Hyperplasia? Result?
21-Hydroxylase deficiency
- Salt wasting
- Elevated DHEA, androgen/estrogen pathway [early onset- clitoral enlargement; late onset- sexual precocity, hirsutism]
What is the most common and most severe clinical effect of Cushing’s Sydrome?
osteoporosis
What is a major concern of withdrawal from steroid therapy?
Adrenal Crisis
- if pts receiving corticosteroids for >2 weeks, can cause HPA suppression (can take 2-12 mos for return of acceptable HPA function)
- must slowly taper pts off corticosteroids
