Androgens/Antiandrogens Flashcards
What is the major site of androgen synthesis for females?
Zona reticularis
What is the major site of androgen synthesis for males?
Testes
What is the main hormone produced in the zona reticularis
DHEA (dehydroepiandrosterone)
Minor: androstenedione, androstenediol, testosterone
What are the different ways that androgens exist in circulation?
- Testosterone-estrogen binding protein: 30%
- Albumin bound: 68%
- Free: 2%
Active fraction: free+albumin bound
Testosterone can be converted to DHT or estrogen. What is the enzyme of each of those reactions?
Testosterone–>DHT: by 5alpha-reductase
Testosterone–>estrogen: by aromatase(CYP19)
So some of your testosterone gets converted to DHT. It acts on its androgen receptor to cause:
- Development of external genitalia (by the type II 5alpha reductase enzyme). Plays role in differentiation during gestation, and maturation during puberty (growth of penis and scrotum). In adulthood contributes to BPH
- Hair follicles (by type I 5alpha reductase enzyme). Increases hair growth during puberty and later causes facial hair and male pattern baldness.
Some of your testosterone gets converted to estrogen. It acts on its estrogen receptor to cause:
Epiphyseal closure and increased bone density
Some of your testosterone doesn’t get converted to anything and just stays its plain old self. It will act on its androgen receptor and cause:
- Development of internal genitalia, including Wolffian developing during gestation of the seminiferous tubules, seminal vesicles, epididymus, and vas deferences
- Increased muscle mass and strength during puberty
- Deepening of the voice by acting on the larynx
- Erythropoiesis
What is testosterone enanthate used for? What is it?
It is a transdermal testosterone/testosterone ester preparation.
It is used to treat hypogonadism, for example in a solider that had testicle mutilation injuries from IEDs
What is oral hydrocortisone used for?
It is used to treat 21-hydroxylase deficiency (insufficient cortisol production), which is the most common form of congenital adrenal hyperplasia
What does fludrocortisone treat?
It treats 21-hydroxylase deficiency when there is also a deficiency in mineralocorticoids
What are some treatments (3) that can be used for the treatment of andropause, which refers to the 1-2% decrease of testosterone concentration every year after 30
- Testoderm patch: tape patch onto scrotum
- Androderm patch: same as #1 but with skin permeation enhancers
- AndroGel (testosterone gel you rub on your shoulders lol)
What are Danazol and Stanozolol used for?
Hereditary Angioedema: in this disease, an impaired C1-esterase inhibitor causes overactivity of the complement cascade, leading to increased blood vessel permeability. This androgen preparation stimulates your liver to make the inhibitor of the esterase enzyme. Must be taken ORALLY and must contain the 17alpha-aliphatic group to be effective
Why can testosterone be used as a treatment for hemolytic anemia
Because, remember, testosterone can stimulate erythropoiesis!
What’s the big deal about 17-alpha and 17-beta modification of androgens
17-alpha modification (oral agents): this is what is done in oral androgens, and this makes them weak, unable to promote spermatogenesis, but it can cause liver damage.
17-beta modification (injectable agents): prolongs their absorption