Steroid Hormones Flashcards
Where is cholesterol found?
Free in membranes
Esters in the liver
Name a glucocorticoid?
Cortisol
Name a mineralocorticoid?
aldosterone
What drug blocks estrogen?
tamoxifen
What drug lowers testosterone?
Leuprolide
cholesterol comes from?
acetyl CoA
Steroids eliminated by which CYP?
CYP 3A4 (most abundant in human body)
tamoxifen does what?
lowers estrogen
Leuprolide does what?
lowers testosterone
How does sex steroids enter cell?
through cell membrane directly into nucleus
how do mineralo and glucocorticoids enter the cell?
enters cell, binds to steroid-receptor
What is activated to bind to DNA?
Hormone response enzyme. HRE
What does Cyproterone acetate do and what does it treat?
blocks androgen synthesis treats: 1. hirsutism 2. for male to female gender change 3. chemical castration
Aldosterone comes from which layer?
Glomerulosa
Cortisol comes from which adrenal layer?
fasciculata
Mineralocorticoids function?
sodium and retention
aldosterone secretion mediated by? 3 things
Angiotensin II
ACTH and potassium
when there is no hormone in cytosol, what does the steroid receptor bind?
heat shock proteins to prevent transcription
DHEA does what to cortisol?
opposes it.
Anabolic androgen
cortisol in blood is bound to?
transcortin
How does glucocorticoids suppress immune system?
TNF-a usually kicks off IkBa(inhibitor), but Glucocorticoids elevates the level of inhibitors opposing the production of cytokines
Dexamethasone used as a?
anti-inflammatory
immunosuppresant
How potent is dexamethasone compared to cortisol? prednisone?
20-30x more than cortisol
4-5x more than prednisone
why give dexamethasone before antibiotics in meningitis?
prevent inflammatory response in brain to killed bacteria
how treat altitude sickness with glucocorticoid?
Give dexamethasone
Beclomethasone administration usually?
nasal spray
what is critical when stopping oral steroids?
progressively reduce dosage
What is Leuprorelin? when use it?
blocks GnRH stim, inhibits FSH/LH release: chemical castration
treat breast/ovarian, prostate cancer
sex steroids in blood bind to?
sex hormone-binding globulin
95% of testosterone is produced by which cells?
Leydig Cells
Which area of adrenal produce testosterone?
zona reticularis
what needs testosterone for spermatogenesis?
sertoli cells
why block sex hormones in prostate/breast cancers
cancer cells retain some lineage characteristics and are affected by deprivation of its hormones
