male reproductive hormones Flashcards
where does testosterone come from in males ?
leydig cells
where is DHT made ?
made in the peripheral tissue through the conversion of testosterone to DHT through the enzyme 5 alpha reductase
what is the mechanism of finasteride ?
inhibition of 5 alpha reductase
how is estradiol formed ?
conversion of testosterone into estradiol through aromatase
this occurs in adipose tissue
what drives the growth of the testes in males ?
SRY gene which produces the testis determining factor
what is the male genitalia divided into and what are their origins ?
internal genitalia - derived from the mesonephric ducts
external genitalia - derived from the urogenital sinus
what hormones are needed for the development of the internal genitalia and the external genitalia ?
internal genitalia - testosterone
external genitalia - DHT
what is the mode of inheritance of 5 alpha reductase ?
autosomal recessive
what is the presentation of 5 alpha reductase deficiency ?
normal internal genitalia
absent external male genitalia
what is the classic case associated with 5 alpha reductase ?
1- male with ambiguous genitalia
2-female child with masculinization at puberty
3- blind vagina
4- absence of uterus
what is the growth spurt driven by ?
estrogens
what is the key androgen associated with androgenic alopecia ?
DHT
what is the mosyt common cause of male hypogonadism ?
aging
what are the ptential adverse effects with exogenous testosterone ?
increase in hematocrit
acne
balding
worsening BPH
decreased spermatogenesis
what is thr MOA of spironolactone ?
potassium sparing diuretic
what is the key side effect of spironolactone in men ?
gynecomastia
due to blockage of androgen receptors
what are the uses and side effects associated with spironolactone in women ?
uses : may be used for hirsutism , acne
side effect: amenorrhea
what receptors are activated by spironolactone ?
activates progesterone receptors
what drug is an alternative to spironolactone that doesn’t cause gynecomastia ?
eplerenone
what are sertoli cells stimulated by ?
FSH
what do sertoli cells secrete ?
inhibin B - which inhibits FSH
androgen binding protein
anti mullerian hormone
what is CAIS ?
complete androgen insensitivity syndrome
no receptors to the androgens
no external or internal male genitalia present
what is the presentation of CAIS ?
amenorrhea
abdominal testes
a child who presents with an abdominal mass at puberty - biopsy it to be testes
what is the effect of temperature on the testes ?
spermatogenesis requires lower temperatures
what is cryptorchidism ?
hidden testes
undescended
what are the complications of cryptorchidism ?
low sperm count
low inhibin levels
higher risk of germ cell tumors
testicular torsion
inguinal hernia
what is the treatment of cryptorchidism ?
orchiopexy
what is the dangerous cause of bilateral undescended testes ?
congenital adrenal hyperplasia
what is varicocele ?
dilatation of the pampiniform plexus
what is the cause of varicocele ?
obstruction of the outflow of venous blood
more common in the left side
what is varicocele associated with ?
renal cell carcinoma
