Steriods Flashcards
What is the precursor of steriods?
Cholesterol
What parts of the adrenal gland are the steriods produced?
Zona Glomerulosa (edge) - Aldosterone Zona Fasciculate (cortex) - Cortisol
Where are steriods metabolized at?
Deactivated in the Liver by conjugation and reduction of A ring.
How do steriods bind and elicit effects?
They bind to a receptor intracellularly and become a transciption factor for gene products to express effects.
What are effects of cortisol?
Increases blood glucose, increases liver glycogen and gluconeogenesis, increased urinary nitrogen excretion, and amino acid mobilization, reduces peripheral glucose utilization.
How does Cortisol block inflammation?
Causes upregulation of IKBalpha, which binds NFkB preventing induction of inflammation.
What effect does cortisol have on lipid metabolism?
Cortisol mobilizes lipids and redistributes the fat, which is the reason for “moon face”.
How does the body prevent cross over binding of mineralcorticoid and cortisol?
Cells that contain mineralcorticoid receptors also express 11B-hydroxysterol dehydrogenase, which converts cortisol into cortisone that doesn’t bind.
What can cause inhibition of 11B-hydroxysterol dehydrogenase?
Licorice, causing hypokalemia and hypernatriemia with hypertension. (Cortisol binds mineralcorticoid receptors)
How does aldosterone work?
In the kidney, binds in the collecting duct, upregulates ENac Channels and Na/K ATPase to increase sodium absorption and increase blood pressure.
What do glucocorticoids do to immune cells?
Sequesters them in the spleen and bone marrow. Prevent endothelium from production of adhesion molecules by inhibiting NFkB.
How do glucocorticoids work?
Prevents the release of arachdonic acid.
Why shouldn’t you suddenly stop taking glucocorticoids?
Glucocorticoids suppress ACTH, which causes adrenal gland to produce steroids, but takes several weeks for ACTH to increase after stopping steroids (long term use). Sudden stopping can cause Adrenal Insufficiency.
What is a contraindication of giving steriods to a patient?
Infection, due to the immunosuppressive properties.
How can Metyrapone be used?
Metyrapone inhibits synthesis of cortisol in the adrenal gland, but the metabolite doesn’t suppress ACTH, so can test to see if the pituitary is working properly.
