Estrogens Flashcards
What is the most common estrogen produced by the ovaries?
E2- estradiol
What are E1, E2 and E3?
E1- estrone
E2- estradiol
E3- estriol
What is the purpose of estrogen?
Development of female reproductive organs, secondary sexual characteristics, and the menstrual cycle.
Where and how are E1 and E3 produced? (2 ways)
In the liver via E2.
Adrenal cortex from androstenedione. (Or other androgens).
Which form of estrogen is most common in post menopausal women?
Estrone (E1)- from the adrenal Cortex
E2 is produced by…
Follicular cells and progesterone by the corpus luteum.
What is SHBG?
Sex hormone binding globulin.
Which estrogen binds the strongest to SHBG?
E2
E1 and E3 have weak affinity for ER (estrogen receptor)
How does the liver effect estrogen?
1st pass effect and entero-hepatic recycling.
Pharmacodynamics of estrogen.
ER has nuclear localization. ER dimer binds ERE in the promoter regions of estrogen-responsive genes.
3 synthetic estrogen mimicking steroids:
Ethinyl estradiol
Mestranol
Quinostrol
3 synthetic non-steroidal estrogen mimicking agents:
Diethylstilbestrol
Chlorotrianisene
Methallenestril
Estrogen mimicking phytochemicals
Flavonones: genistein(soy) and resveratrol(red wine)
Estrogen mimicking pesticides
Kepone, bisphenol, hexachlorophene
What is hypogonadism and how do you treat it in women?
Lack of maturation and development of secondary sexual characteristics.
Estrogen
Endometrial development and shedding during menstrual cycle is regulated by:
Estrogen
Excessive exposure to estrogen can cause:
Endometrial hyperplasia and abnormal bleeding.
How can lack of estrogen lead to osteoporosis?
Estrogen INHIBITS osteoclasts cells thus preventing bone reabsorption.
Estrogen accelerates or decelerates bone growth and epiphyseal closure?
Accelerates
Why is estrogen protective against atherosclerosis?
Increases hdl and lowers LDL.
Estrogen increases what liver proteins?
CBG, SHBG, TBG, transferrin, renin substrate, fibrinogen.
How does estrogen increase risk of stroke and cardiovascular disease?
Decreases anti thrombin 3 activity which increases coagulation. (Mostly in hrt)
What post menopausal symptoms does estrogen help with?
Vasomotor symptoms (hot flashes)
What is HRT and who is it used for?
Hormone replacement therapy
Post menopausal women and those with radical hysterectomy
3 benefits of HRT.
Prevents osteoporosis
Reduces vasomotor symptoms/genital atrophy
Protective anti Alzheimer’s effects
Risks of HRT (4).
Breast cancer, endometrial carcinoma, coagulation and stroke.
What can you take to reduce osteoporosis risk?
Calcium + D (and weight bearing exercise)
Adding progestins to estrogen does what in terms of cancer?
Increases risk of BC but lowers risk of. Endometrial carcinoma.
When giving estrogen and progestin as ERT how would split up the days?
Estrogen as the first 25 days and progestin during the last 10-14 days.
What is the name for combined estrogen-progestin?
Medroxyprogesterone
Medroxyprogesterone can cause…
Amenorrhea
Estrogen-progestin combos can be used to treat… (2)
dysmenorrhea or amenorrhea + hirsuitism due to excess androgens
AEs of estrogen treatment
postmenopausal uterine bleeding–possible b/c of edometrial hyperplasia/carcinoma (dec risk with progesterone)
Breast cancer (dec with tamoxifen)
Which form of estrogen is teratogenic, can give daughters of using mothers vaginal adenomas, and must be avoided during pregnancy?
Diethystilbestrol (DES)
When is estrogen CI’ed?
estrogen dependant cancers (endometrial/BC/family hx)
undiagnosed vaginal bleeding
liver disease
thromboembolic disorders
heavy smoker over 40!
