Women's Corner
Women's Corner
- The exact pathogensis is unknown , however it should not be regarded as a disease , but a symptom complex associated with chronic anovulation- The hyperandrogenism and anovulation in PCO may be caused by an abnormality in 4 endocrinologically active compartments :
1. The ovaries
2. The adrenal glands
3. The periphery : The skin and adipose tissues
4. The Hypothalamo-pituitary compartment .
· The ovarian comparment :
- The most consistent contributor of androgens
- Dysregulation or hyperfunctioning of the cytochrome p-450c17 (17 OHase) , the androgen forming system in both the adrenals and the ovaries, may be the main pathogenetic mechanism underlying hyperandrogenism . This dysregulation renders the ovaries more sensitive to the action of the pituitary gonadotropins . Thus ovarian stroma are stimulated by LH and contribute to ovarian hyperandrogenism .
- The high intrafollicular androgen concentration inhibit follicular maturation which results in inactive granulosa cells with minimal aromatase activity .
· The adrenal compartment :
- The concept is that PCO is an exaggerated adrenarche
- Hyperfunctioning of the P-450c17 (hydroxylase) and P-450c17(17-20 desmolase) produces elevated DHAS . However DHAS is elevated only in 50% of cases .
- Evidence of adrenal contribution :
1. Elevated DHAS in 50%
2. Elevated urinary 17-ketosteroids in 20%
3 In primary adrenal disease there is PCO like picture .
· Peripheral compartment :
This manifests its contribution in several ways :
1. The presence of 5 -reductase activity in the skin largely determines presence or absence of hirsutism .
2. Aromatase activity is increased in the fat cells and peripheral aromatization is increased proportionately with the body weight . This increases estrone levels . Thus a chronic hyperestrogenic state occurs and results in reversal of E1:E2 ratio .
3. the metabolism of estrogen is reduced due to decreased 2-hydroxylation and 17-oxidation .
· The hypothalamo-pituitary compartment :
As a result of chronically elevated estrogen levels :
- An increased LH pulse frequency due to increased GnRH pulse frequency
- FSH is not increased with LH , probably because of the synergistic negative feed-back of chronically elevated estrogens levels and increased inhibin .
- About 25% of patients with PCO exhibit elevated prolactin levels . It is postulated that hyperprolactinemia may be due to decreased dopamine
Increased endogenous opiates as B-endorphins
dr. Hisham Al-Inany Lecturer in Obstetrics and Gynecology Department, Cairo University, Egypt Dr. Amr Hussein Lecturer in Obstetrics and Gynecology Department, Cairo University, Egypt