Sex Hormones

Question 1

Chorionic Gonadotropin is produced by which specific organ in the body? And which receptor in the body does it interact with?

Answer 1

Produced by fertilized ovum. It interacts with LH receptors.

Question 2

Estrogen synthesis requires stimulation of which hormone(s):

a) LH
b) LH and FSH
c) FSH
d) none of the above

Answer 2

b) LH and FSH

Question 3

What is the function of LH in males?

Answer 3

Stimulates the synthesis of testosterone by the Leydig cells of the testes

Question 4

What is the function of LH in females?

Answer 4

It induces ovulation (LH peak) and stimulates progesterone and estrogen synthesis.

Question 5

What is the function of FSH in males?

Answer 5

Promotes spermatogenesis (Testosterone also required)

Question 6

Define hypogonadotrophic hypogonadism

Answer 6

Failure of hypothalamus to secrete GnRH or pituitary to secret gonadotropins. (Also known as Secondary gonadal failure)

Question 7

What happens in primary gonadal failure?

Answer 7

Ovaries/testes fail to respond to stimulation by gonadotropins; you’ll see increase in FSH and LH but no sex steroids produced

Question 8

What are the 3 types of gonadotropins and what are the differences?

Answer 8

Menotropins - FSH and LH
Urofollitropin - FSH only
Chorionic gonadotropin

Question 9

What is Gonadorelin? What is it used for?

Answer 9

Synthetic version of GnRH; used to promote LH release and ovulation in women with infertility due to impaired GnRH release
(Note: pulsatile administration by IV or SC)

Question 10

Explain the mechanism of GnRH agonists in decreasing release of Gn and sex steroids.

Answer 10

GnRH agonists have increased affinity for GnRH receptors on the pituitary gland and they are less susceptible to proteolysis.
Initially there is an agonist phase which is followed by antagonist phase after continual administration due to down-regulation of GnRH receptors (overstimulation). = less active GnRH receptors = decrease production of Gn and sex steroids

Question 11

What are some conditions in which we want to suppress Gn and sex steroids secretions?

Answer 11

Endometriosis
Advanced prostate Ca
Precocious puberty
Uterine fibroids
Hyperandrogenism in women

Question 12

What are some adverse effects of GnRH agonists?

Answer 12

Women: decreased BMD, hot flashes, vaginal dryness, memory impairment
Men: hot flashes, decreased libido, ED, increased risk of osteoporotic fractures, type 2 diabetes and CV disease

Question 13

Why might we give estrogen to women on GnRH agonists?

Answer 13

Used as “add-back therapy” - to minimize effect on bone density

Question 14

What is the indication of Buserelin? And what dosage forms does it come in?

Answer 14

Palliative treatment of advanced prostate cancer; Endometriosis.
It comes in SC injection and nasal spray.

Question 15

What is the indication of Leuprolide? And what dosage forms does it come in?

Answer 15

Palliative treatment of advanced prostate cancer
SC injection (depot)

Question 16

What is the indication of Nafarelin? And what dosage forms does it come in?

Answer 16

Endometriosis; comes in nasal spray

Question 17

What agents can we use to reduce a “flare” of disease activity in prostate cancer patients after starting GnRH agonist?

Answer 17

Androgen receptor antagonist or GnRH antagonist

Question 18

Give 3 names of GnRH antagonists.

Answer 18

Ganirelix, Cetrorelix, Degarelix

Question 19

What are GnRH antagonists used for?

Answer 19

Prevent premature LH surge and ovulation in in vitro fertilization cycles and for use in advanced prostate cancer