Steroids Flashcards
Name the sex steroids
Androgens
Estrogens
Progestagens
What is the receptor for testosterone?
Nuclear androgen receptor
What does Leuprolide do?
Lowers testosterone
What is the primary mineralocorticoid?
Aldosterone
What is the physiological effect of aldosterone?
Increased reabsorption of sodium and water > increase blood volume and pressure
What is the precursor steroid of oestrogen?
Testosterone
What does Corticotropin releasing hormone control?
Corticosteroids
Which P450 eliminates steroids?
CYP3A4
In general terms, how do glucocorticosteroids depress the immune system?
Inhibit cytokine production
Which steroid does dexamethasone mimic?
Cortisol
What are androgens?
The class of steroids that control male development - eg testosterone
Do women produce testosterone?
Yes - a small quantity in the ovaries and placenta
When is cyproterone acetate indicated?
Hirsutism in females
Male to female sex change
- as it blocks the effect of testosterone
What are the effects of exogenous anabolic steroids?
Increase production of actin and myosin
Block the protein catabolism by cortisol
Increase BMR to reduce fat
What is cyproterone acetate?
A synthetic steroid inhibitor of androgen receptor
What stimulates cortisol synthesis and release?
ACTH
What are the controllers of aldosterone production?
Angiotensin II
Adrenocorticotrophic hormone (ACTH)
Local K levels
What are the physiological effects of cortisol?
Stimulate protein catabolism
Inhibit protein synthesis
Increases blood glucose level
Inhibits the utilisation of glucose by adipose tissue
Facilitates lipid breakdown in major adipose tissue to FAs
Promotes weight gain by stim. appetite and excessive eating
Which part of the adrenal gland produces cortisol?
Zona fasciculata
What is tested for in pregnancy tests?
hCG - human chorionic gonadotropin
How are sex steroid levels altered in breast and prostate cancer treatment?
They are lowered
Where in the cell does squalene get converted into cholesterol?
ER
What is the major glucocorticoid steroid?
Cortisol
Where is aldosterone produced?
The adrenal cortex
Where is GnRH released?
Gonadotrophin releasing hormone - the hypothalamus
What is the name of the important enzymes in the cholesterol synthesis pathway?
HMG-CoA reductase
Which steroid is indicated in asthma?
Prednisolone
What is the carrier molecule for sex steroid in the blood?
Sex-hormone binding globulin
What is 17beta-estradiol?
The primary female sex hormone - comes from progesterone
What are the types of corticosteriods?
Glucocorticords and mineralocorticoids
How are signals from steroids transducted in their target cells?
Binding to nuclear receptors and changing gene expression
Which cells produce testosterone?
Leydig
Which steroid is the most abundant?
Cholesterol
What is Beclomethasone nasal spray indicated for?
Treat nasal symptoms of allergies
What is difference between the signal transduction of sex steroids and adrenal steroids?
Adrenal steroids bind to a cytoplasmic receptor which is inhibited by a heat shock protein
The sex steroids bind to a nuclear receptor in the nucleus that isn’t inhibited
What is leuprorelin? What is its physiological effect?
An analogue of gonadotropin-releasing hormone - blocks the stimulation of its receptor therefore blocking stimulation of secretion of LH and FSH
What does Tamoxifen do?
Partial agonist of oestrogen receptor in
Uterus, bone and CVS
Antagonist in breast and CNS
What does renin do?
Converts angiotensinogen to angiotensin I
