Progestins, estrogens & androgens Flashcards
Role of FSH
stimulate estrogens and follicular growth
-always inhibitory to Pit/Hypothalamus
Role of LH
stimulate ovulation, progesterone
-inhibitory early, stimulatory mid-cycle
aromatase enzyme
present in granulosa cells of ovaries
- synthesizes estradiol and estrone from testosterone and androstenedione
- also called CYP19A1
estrogens: main and action
- estradiol-17B
actions: stim growth and dev of the mammary gland - promote endometrial proliferation during follicular phase
- promote proliferation of the vag epithelium
- block reabsorption of bone
- increase HDL and decrease LDL
- increase risk of thromboembolism
- increase incidence of endometrial/breast ca
- increase progesterone receptors
progestins: main and actions
- progesterone
- promotes endometrial dev during luteal phase
- main determinant of the onset of menstration
- decreases amt of cervical mucus and increases viscosity
- increases body temp
- stim growth and dev of mammary gland during pregnancy
- uterine effects are essential for maintenance of preg
- weak mineralocortiocoid antagonist
general properties of estrogens and progestins
progesterone and estradiol are rapidly inactivated when taken orally
- synthetic analogs are more useful but then cross-rxn with other steroid receptors and act as agonists or antagonists
- many routes
drospirenone
-progesterone analog with increased activity as MC antagonist and androgen antagonist
ulipristal
- selective progesterone receptor modulator (SPRM)
- postcoital contraceptive
- more effective than norgestrel and maintains efficacy longer
- can be agonist or antagonist, dep on tissue
diethylstilbestrol (DES)
-non-steroidal estrogen, 1st
Hormones that can be used for contraception
-P, E, SPRM
Hormones that can be used for suppression of the hypothalamic-pituitary gonadal axis
P, E
hormones that can be used for hormone replacement therapy
P, E, SERM
hormones that can be used for abortion
P antagonists
hormones that can be used for ovulation induction
E antagonists, aromatase inhibitors
hormones that can be used for breast ca therapy
SERM, aromatase inhibitors
copper IUD
- among the most effective methods of contraception
- copper is spermicidal
- in theory, could prevent implantation, but fertilization would have had to occurred prior to insertion
norethrindrone
a progesterone analog
- used as an oral contraceptive agent
- also present in IUD
medroxyprogesterone acetate
Depo-provera
- IM injection q 3 mo
- progesterone analog used as contraception
- decreased bone density
norgestrel
-progestin analog
-present in IUD
-present in post coital contraceptives (plan B)
(higher dose than routine contraception, prevents ovulation)
progestin analog MOA
- prevent fertilization by decreasing amount and increasing the viscosity of cervical mucous
- prevent ovulation by inhibiting gonadotropin secretion
progestin analog SE
- h/a
- abnormal bleeding
progestins and estrogens as contraceptive agents
-oral
21 on, 7 off
-usually contain norethindrone and ethinyl estradiol
-monophasic (constant E & P for 21 days)
-biphasic (constant E for 21 days, progesterone low for 1-10, increased 11-21)
-triphasic (constant E 21 days, low P 1-7, increased 7-14, increased again 15-21)
drospirenone/ethinyl estradiol
oral drug
- Yaz
- can prevent acne?