Adrenal Steroids Flashcards
Aldosterone is a gluco or mineralcorticoid?
Minimal glucocorticoid effect
How do we decrease the mineralcorticoid effect of Cortisol?
Mineralocorticoid effect is depleted by 11B-hydroxysteroid dehydrogenase converting cortisol to cortisone
What does 11B-hyroxysteroid DH do?
Converts Cortisol to cortisone which decreases it’s mineralcorticoid effect
What is the glucocorticoid: mineralcorticoid activity of Cortisol?
1:1 glucocorticoid to mineralocorticoid effects (in theory) —> keep in mind it converts to cortisone
Both aldosterone and cortisol act on this receptor
mineralcorticoid receptor
Where is Aldosterone synthesized?
Zona glomerulosa - cholesterol → pregnenolone → desoxycorticosterone → aldosterone
Where is Cortisol synthesized?
Zona fasciculata and reticularis – cholesterol → pregnenolone → desoxycortisol → cortisol
This Steroid has zero mineralcorticoid effect?
Dexamethasone
Does Dexamethasone have glucocorticoid or mineralcorticoid effcts?
Glucocorticoid effects
Prednisolone has how much gluococorticoid:mineralcoid activity?
3:1
Fludrocortisone has how much mineralcorticoid:glucocorticoid activity?
10:1 mineralocorticoid to glucocorticoid
Prevent production of cortisol from deoxycortisol -> no neg. feedback on pituitary -> excess ACTH
Metyrapone
Drug used for Diagnostic test: If given and no large increase in ACTH is noted, the lesion is in the pituitary
Metyrapone
Metyrapone blocks:
11B hyrdoxylase
Metyrapone prevents production of
cortisol from deoxycortisol
What is the result of Metyrapone’s inhibition of 11 B hydroxylase
blocks deoxycortisol—> cortisol thus no negative feedback on pituitary. We expect in health individual to see increase in ACTH
Progesterone and glucocorticoid receptor antagonist
Mifepristone
What do we see in urine as result of Metyrapone?
ACTH stimulates synthesis and excretion of 17-hydroxycorticoids as 11-desoxycortisol
Drug used to terminate pregnancy and tx Cushings disease
Mifeprisone
Spironolactone and Epleronone act on which receptor?
Mineralcorticoid receptor antagonist (aldosterone antagonist)
Steroid drug used to treat HTN (diuretic), heart failure, cardiac hypertroph
Spironolactone and Epleronone
What is special about Spironolactone and Epleronone as far as their diuretic activity?
K Sparing
Progesterone AGONIST. Mineralocorticoid, and androgen receptor antagonist
Drospirenone
Drospirenone is a _______ agonist and _______ and ______antagonist
progesterone Agonist
Mineralcorticoid and androgen antagonist