EXAM #5: ADRENAL AGENTS Flashcards
What hormone is released from the hypothalamus in the HPA axis?
Corticotropin-releasing hormone (CRH)
How does CRH act on in the Anterior Pituitary?
Receptors on the corticotropic cells of the Anterior Pituitary
What is the outcome of CRH activation of the Anterior Pituitary?
ACTH secretion
Where does ACTH exert its action?
ACTH activates receptors on the ADRENAL CORTEX
What happens when ACTH stimulates the adrenal cortex?
1) Increased steroidogenic enzyme expression
2) Stimulation of cortisol and adrenal androgens
What receptors does cortisol bind and activate?
Mineralcorticoid
Glucocorticoid
What happens with activation of the mineralcorticoid and glucocorticoid receptors?
1) Cortisol binds in cytosol
2) Receptors translocate to nucleus to DECREASE gene expression
What is the role of 11B-HSD2?
- Enzyme in minerocorticoid sensitive tissues
- Converts active Cortisol to INACTIVE Cortisone
Elevated levels of Cortisol can overwhelm this enzyme and cause adverse effects
What are the major adverse effects seen with elevated Cortisol levels?
1) Salt/water retention
2) Hypokalemia
3) HTN
What is the role of 11B-HSD1?
Activation of Cortisone to Cortisol
What is the benchmark corticosteroid drug? What is the anti-inflammatory to salt-retaining ratio?
Hydrocortisone
1:1
What is the relative duration of action of Prednisone? What is the anti-inflammatory to salt-retaining ratio?
- Intermediate duration of action
- 4:0.8 ratio
What is the relative duration of action of Dexamethasone? What is the anti-inflammatory to salt-retaining ratio?
- Long duration of action
- 30:0
What is the relative duration of action of Fludrocortisone? What is the anti-inflammatory to salt-retaining ratio?
Mineralcorticoid with 10:125 ratio
Which corticosteroids are prodrugs? How are they activated?
Cortisone and prednisone
*Activated by 11B-HSD1
What is Primary Adrenal Insufficiency or “Addison’s Disease?”
Autoimmune or tuberculoid induced destruction of the adrenal cortex leading to deficiency in cortisol, aldosterone, and androgens
What are the symptoms of Primary Adrenal Insufficiency?
Hypotension
Hyponatremia
Hyperkalemia
Hypoglycemia
How is Primary Adrenal Insufficiency treated?
1) Oral cortisol and liberal Na+ intake
2) Fludrocortisone (mineralcorticoid)
What is Secondary Adrenal Insufficiency?
1) Pituitary disease with a decrease in ACTH production and thus, cortisol
2) Hypothalamic disease with decrease in CRH
- Less ACTH
- Less Cortisol
*Note that because aldosterone is controlled by ACE II, people with secondary pituitary DO NOT have elevated aldosterone
How is Secondary Adrenal Insufficiency treated?
Cortisol