Estrogens and progestins Flashcards
steroidogenesis in the ovary is regulated by what compounds?
LH and FSH (gonadotropins)
which cells are required for estradiol synthesis?
theca and granulosa
what are the features of follicular phase of ovarian cycle?
- high frequency, low amplitude LH secretion
- estrogen rises
- endometrial proliferation
what is the main feature of ovulation? which day does it occur?
estrogen induced gonadotropin surge
day 14
what are the features of the luteal phase of the ovarian cycle?
- rise in estrogen and progesterones
2. endometrial differentiation under control of progesterone
which hormone is absolutely required for ovulation?
LH
what is the effect of estrogen on the endometrium?
endometrial proliferation
what is the effect of progesterone on the endometrium?
endometrial differentiation
preparation for implantation
decrease uterine contractions
how does progesterone influence glucose metabolism?
leads to glucose intolerance
which hormone is the key regulator during the luteal phase of the menstrual cycle?
progesterone
which hormone is the key regulator during the follicular phase of the menstrual cycle?
estrogen
what are the effects of estrogen on lipids?
decrease LDL
increase HDL
increase TGs
what is the effect of estrogen on bone?
antiresorptive
what is the effect of estrogen on the liver?
increase plasma proteins
what are the effects of estrogen on the blood?
increase coag factors
decrease antithrombin
what is important about ethinyl estradiol?
addition of ethinyl group to estrogen increases half life up to 13-27 hours
what are the risks of long term estrogen plus progesterone in healthy postmenopausal women?
increased coronary heart disease
increased stroke
increased PE
increased invasive breast cancer
what is the main mechanism of estrogen use on contraception?
negative feedback pressure on HPG axis
suppresses LH surge
what is responsible for suppression of acne in birth control?
estrogenic component of BC preparations
how does estrogen inhibit acne?
inhibits steroidogenesis
decreases free testosterone concentrations
what are the adverse effects of estrogen?
breast tenderness
endometrial hyperplasia
increased blood coagulation
in which situation can you use estrogen alone for hormone replacement therapy?
hysterectomy - no risk of endometrial cancer
what are the two backbone molecules for the progestins?
progesterone
19-nortestosterone
what are the important progestins?
medroxyprogesterone (MPA)
norethindrone
norgestrel
how do progestins differ from estrogens for ovulation? what about for BC in general? why?
progestins are less efficacious than estrogens at suppressing ovulation
for BC, they are just as efficacious
progestin effect on cervical glands (increasing viscosity)
what are the therapeutic uses for progestins?
contraceptives
HRT
dysmenorrhea
endometriosis
what is the risk of unchallenged estrogen use?
continued proliferation
what is the rationale for progestin use in HRT?
decrease risk of endometrial hyperplasia caused by estrogens
what is the rationale for progestin use in dysmenorrhea?
decrease endometrial mass and PG production
what is the rationale for progestin use in endometriosis?
decrease endometrial proliferation by regulating ER expression and stimulating differentiation of endometrial cells
what are the adverse effects of progestin use?
breakthrough bleeding impaired glucose tolerance hirsutism acne lipid metabolism
what are the general MOAs of combined estrogen-progestin BC and progestin-only pills or implants?
- prevent pituitary release of hormones that stimulate ovulation
- suppress LH and FSH surge
- alter cervical mucus
- alter endometrium
which oral BC pill is progestin only?
norethindrone
what are the contraindications of estrogen containing contraceptives?
- known or suspect breast cancer
- thromboembolic disorders
- liver disease
- CV disease hx
- smokers 35 yo or older
