6 Endocrinology: Adrenal Hormones Flashcards
The 5 general functions of cortisol are? (global card)
- Mobilize/make glucose (plus stop using & store glucose)
- Mobilize amino acids and send them all to the liver
- Mobilize Fatty Acid (FA) stores
- Suppress immunity/inflammation
- Mature the CNS, retina, skin, lungs
What a simple way to remember catecholamine (from adrenal medulla) effects? (global card)
They are like thyroid hormone, but:
- No CNS effects
- Spares protein
- Short-acting
The 3 zones of cortex G-F-R release what hormones?
aldosterone, glucocorticoids, androgens
[deeper you go, sweeter it gets]
Which: cortex, or medulla? Is a modified sympathetic ganglion (lacking a post-ganglionic axon)
Medulla
Adrenal Medulla releases what?
catecholamines (norepi, epi) in response to sympathetic stimulation
Blood flow which direction in the adrenal glands? why does this matter?
- cortex->medulla
- One-two punch of hormones, and cortisol causes norepinephrin to become epinephrine.
So, what ARE the effects of catecholamines? (global card) (think of sympathetics)
- Up cardiac output, ventilation
- Mobilize fats
- Mobilize/make glucose but…
- Send all glucose to the brain
- Dilate pupils
- Decrease digestion
- Up muscle tension, neuromuscular transmission
The 4 catecholamine receptors are alpha 1 & 2, beta 1 & 2. Which catecholamine does not act on all 4?
Norepi (Doesn’t do beta 2’s)
What are catecholamines made from?
tyrosine
What is the steps by which catecholamines are made?
tyrosine-> L-Dopa-> Dopamine-> Norepi-> Epi
Which step of catecholamine synthesis is not regulated by ACTH, but by cortisol?
Norepi->Epi
Pheocromocytoma is a tumor where? Are symptoms continuous or sporadic?
- Adrenal medulla (chromaffin tissue)
- Sporadic
Pg. 6 has a figure showing cholesterol synthesis into steroids, tons of steps so easier to see in a graphic.
Now I’ll ask you 2 questions about it…
What receptor brings cholesterol into cells?
LDL receptor (also Acetyl CoA can be made into cholesterol)
What enzyme converts cholesterol into pregnenalone once StAR protein brings it into the mitochondria?
desmolase
As steroids, How are cortisol and aldosterone circulated?
Either bound or free
[cortisol w/ transcortin or albumin, aldosterone w/ plasma proteins]
What organ inactivates steroids?
liver!!!!!!!!!!!!!
What does aldosterone do? What would happen if you had too much/too little?
- Na reabsorb, K secrete
- Exactly what you would expect, EXCEPT in hyper-aldosterone, “escape” increases GFR and allows fluids and Na to leave body
As a steroid, where is aldosterone’s receptor located?
cytoplasm
As a steroid, what happens once aldosterone binds receptor?
disassociate hsp90, heads into nucleus, becomes a transcription factor
11 beta hydroxysteroid dehydrogenase Type 2 does what?
Degrades cortisol so it doesn’t bind aldosterone’s receptor and mimic aldosterone’s effect (licorice & stevia inhibit this enzyme, causing up blood pressure….)
What organs do the following: Secretes angiotensinogen? Secretes renin? Converts angiotensin 1? produces aldosterone?
- liver
- kidney
- lungs
- adrenal cortex
In order of importance, what causes aldosterone secretion?
-Up K+
-Renin system
-Down Na+
-ACTH
[ANP prevents secretion]
How does cortisol cause anti-inflammation? (global card)
- stabilize lysosomes
- decrease capillary permeability
- decrease WBC migration and phagocytosis
- decrease cellular glucose usage
- drops immune cell proliferation/Ab production
- inhibit NF-KappaB
