Endocrine Control Female Reproduction 8

Question 1

What are the hormonal imbalances in PCOS that lead to androgen production?

Answer 1

• Increased frequency of GnRH secretion
  
  • selectively increases LH release
  • simultaneously suppresses FSH secretion
• Pituitary sensitivity to GnRH increased
  
  • estrogen mediated
• Increased LH levels stimulate increased ovarian theca cell androgen production

Question 2

What are some factors that potentiate the androgen concentration in women with PCOS?

Answer 2

• Acyclic FSH secretion results in arrested ovarian follicular development
  
  • Granulosa cells do not develop sufficient aromatase capacity to completely aromatize androgens into estrogens
• Often there is increased adrenal androgen production

Question 3

How does high androgen affect LH release in PCOS? What is the remedy?

Answer 3

• Androgens important for pathogenesis of increased LH release
  
  • causes insensitivity of hypothalamic GnRH pulse generator to normal feedback of estrogen and progesterone
• Normal feedback can be restored by androgen receptor blockade

Question 4

What is the role of hyperinsulinemia in PCOS?

Answer 4

Amplifying both steroidogenic and gonadotropin secretory abnormalities.

Question 5

What are the intrinsic ovary abnormalities in PCOS?

Answer 5

• Both ovulatory and anovulatory PCO, proportion of primary follicles significantly increased
  
  • reciprocal decrease in proportion of primordial follicles
• Theca cells from PCO have constitutive increases in activity of multiple steroidogenic enzymes
  
  • similar defect leads to adrenal androgene excess