Glucocorticoids and Mineralocorticoids Flashcards
2 Main parts of Adrenal Gland and the substances they produce
Adrenal Cortex = Corticosteroids
Adrenal Medulla = Catecholamines
3 Main types of Corticosteroids, their site of production and their stucture
Mnemonic: MGA GFR (outer to inner).
From outer to inner layer:
Zona Glomerulosa - Mineralocorticoids (21 C)
Zona Fasciculata - Glucocorticoids (21 C)
Zona Reticularis - Androgens (19 C)
What are the fight or flight hormones?
Adrenal Medula secretion –> Catecholamines:
Epinephrine/ Adrenaline
Norepinephrine/Noradrenaline
What is the precursor of all steroid hormones, glucocorticoids, mineralocorticoids and sex hormones?
Cholesterol!
All the products derived from cholesterol are steroids (T/F)
T. Pero preferred lang tawagin na cortisol at glucocorticoid
Mineralocorticoids:
What is the Major mineralocorticoid produced? Function?
Aldosterone.
Acts on the DISTAL PORTION of convoluted tubule to promote Na reabsorption and K excretion.
Basta MINERALocorticoid = aldosterone = Na and K (Mineral —> ions …ewan, basta)
What controls secretion of aldosterone?
Primarily: RAAS
Secondary: ACTH
Mineralocortioid Receptor is highly specific. (T/F)
F. It can also bind with glucocorticoids (ex. cortisol)
Why? Since Mineralo- and Gluco- are higly similar in structure.
When administering doses of cortisol, its possible to observe hypertension and hypokalemia. (T/F)
T.
Hypertension and hypokalemia is caused by high doses of aldosterone which is almost similar, in structure, to cortisol
Blood levels of Cortisol is 2000x higher than Aldosterone. How can aldosterone stimulate SPECIFIC biological effects?
Target cells for aldosterone has an enzyme which can target cortisol and convert it into cortisone (has lesser affinity to Mineralo- Receptor). With this, aldosterone can now easily bind to Mineralo- Receptor
Mineralocorticoids:
What are its effects on the body?
[Think about Na+ and K+]
[Na+] Sodium Retention —> leads to hypertension, edema and heart failure
[K+] Potassium Excretion —> Hypokalemia —> leads to muscle weakness and metabolic alkalosis.
FLUDROCORTISONE is a distinct mineralocorticoid agonist only for mineralocorticoid receptors. (T/F)
F.
FIRST, it is a actually a glucocorticoid.
It has glucocorticoid activity when given at high concentrations and mineralocorticoid activity at low concentrations.
At what dose should you administer Fludrocortisone for it to exhibit a salt-retaining activity (bale mineralocorticoid activity)? Does this dose have significant anti-inflamm effects?
0.1 mg given 2-7 times per week.
The dosage is too small to have significant inflammatory effects.
Glucocorticoids Characteristics:
When does blood conc of glucocorticoids increase?
During stress (mental, emotional, etc)
Glucocorticoids Characteristics:
Do glucocorticoids have immunosuppressive, metabolic and anti-inflammatory effects?
Yes. For metabolic, the inc. glycogenolysis, gluconeogenesis, proteolysis and lipolysis.
They also reduce the activity of the innate and acquired immune systems.
Glucocorticoids Characteristics:
What is the Permissive Effect?
Catecholamines causes vasoconstriction. The presence of glucocorticoids further enhance the vasoconstrictive effects of catecholamine such that it can reverse hypotension.
Glucocorticoids Characteristics:
What is the main endogenous glucocorticoid? How much of it is physiologically secreted by the body per day?
Cortisol (a.k.a. Hydrocortisone)
~20mg/day (15-30mg/day)
Glucocorticoids Characteristics:
Describe the chain of events that lead to cortisol production.
Stress —> stimulate Hypothalamus to secrete Corticotropin releasing hormone —> signals Ant. Pituitary gland to release Adrenocorticotropic Hormone —> tells adrenal gland to secrete cortisol