Hypothalamic and Pituitary Hormones 1.3

Question 1

Gonadotropins act through what?

Answer 1

GPCR

Question 2

Clinical applications of Gonadotropins

Answer 2

1) Ovulation Induction

2) Male infertility (req both FSH and LH)

Question 3

AE of gonadotropins in Women

Answer 3

1) Ovarian hyperstimulation syndrome
2) Multiple pregnancies
3) Headache, depression edema, precocious puberty

Question 4

AE of gonadotropins in Men

Answer 4

Gynecomastia

Question 5

Gonadorelin

Answer 5

Gonadotropin-releasing hormone

Question 6

Gonadotropin-releasing hormone analogs

Answer 6

1) Goserelin
2) Leuprolide
3) Nafarelin

Question 7

What type of GnRH secretion is required to STIMULATE release of LH and FSH?

Answer 7

Pulsitile

Question 8

What type of GnRH secretion is required to INHIBIT FSH and LH release (men & woman) leading to hypogonadism.

Answer 8

Sustained nonpulsatile

Question 9

What is unique regarding GnRH analog administration?

Answer 9

Biphasic response:

• agonist flare in first 7 days
• chronic effects (> 1 week) = inhibitory action (due to receptor down-regulation & changes in signaling pathways

Question 10

Clinical application of GnRH for males with infertility

Answer 10

In men with hypothalamic
hypogonadotropic hypogonadism (pulsatile gonadorelin)

Question 11

Besides infertility, another stimulation application for GnRH analogs

Answer 11

Diagnosis of LH responsiveness: Whether delayed puberty is due to constitutional delay or hypogonadotropic
hypogonadism

Question 12

Indication for when GnRH and analogs are used for suppression:

Answer 12

1) Controlled ovarian hyperstimulation (leuprolide, nafarelin)
2) Endometriosis (Leuprolide, goserelin, nafarelin)
3) Central Precocious Puberty (leuprolide, nafarelin)
4) Advanced breast & ovarian cancer
5) Treatment of amenorrhea and infertility in women with PCOD
6) Thinning of endometrial lining

Question 13

Notable AE of Gonadorelin

Answer 13

1) Generalized hypersensitivity dermatitis (long term administration)
2) Rare acute hypersensitivity reaction
3) Sudden pituitary apoplexy and blindness (reported in patients with gonadotropin-secreting pit. tumor)

Question 14

Competitive antagonist of GnRH receptors

Answer 14

Centrorelix

Ganirelix

Question 15

Clinical application of GnRH receptor antagonist?

Answer 15

Supression of Gonadotropin Production: Prevention of LH surge during controlled ovarian hyperstimulation