Gonadal hormones Flashcards
Walk through estrogen synthesis from the ovaries.
Pulsatile GnRH stimulates LH and FSH release.
LH stimulates Theca interna cells to produce Desmolase which converts cholesterol to androgens.
FSH stimulates Granulosa cells to stimulates aromatase which takes the androgens that are produced by theca interna cells and converts them to estrogen.
- *ketoconazole inhibits desmolase
- *anastrozole inhibits aomatase
Endogenous estrogens?
Estradiol, Estrone, Estriol
- *estradiol is more potent compared to estrone and estriol
- *50x increase in estradiol and estriol during pregnancy
- *1000x increase in estriol in pregnancy is an indicator of fetal well being
Ethinyl estradiol?
Synthetic Estrogen
MOA - stimulation of estrogen receptors leading to changes in the rates of transcription of estrogen-regulated genes (dimerization in cytosol??)
Clinical uses..
- prevent osteoporosis
- hormone replacement therapy (in post-menopausal women who have undergone ovary removal)
- oral contraceptive therapy
- hypogonadism
- CYP450 metabolism
- Enterohepatic recirculation
AE..
- Moderate toxicity = breakthrough bleeding, nausea, breast tenderness
- Serious toxicity = THROMBOEMBOLISM (estrogens are procoagulants inhibiting protein C and S), gallbladder disease, hypertriglyceridemia, migraine headache, HTN, depression
- breast cancer and endometrial hyperplasia due to unopposed estrogen in postmenopausal women
Mestranol?
Prodrug that is converted to ethinyl estradiol - used in contraceptives
Estrogen esters?
Ex. estradiol cypionate
Long acting estrogens administered IM and used for hypogonadism in young females.
Diethylstilbestrol (DES)?
Non-steroidal estrogen agonist used in pregnancy resulting in female child to infertility and vaginal cancer.
What options are available for hypogonadism in girls/women?
Conjugated estrogens
Ethinyl estradiol
Estradiol esters
What options are available for hormone replacement therapy?
Estrogen component: conjugated estrogens, estradiol, estrone, estriol
Progestin component: progesterone, medroxyprogesterone acetate
What options are available for oral hormonal contraceptives (OC or COC)?
Combined: ethinyl estradiol or mestranol plus a progestin
Progestin only: norethindrone or norgestrel
What options are available for parenteral contraceptives?
-Ethinyl estradiol and norelgestromin as a weekly patch
-Ethinyl estradiol and etonogestrel as a monthly vaginal ring
-L-Norgestrel as an intrauterine device (IUD)
-Etonogestrel as a subcutaneous implant
-Medroxyprogesterone as a depot IM
injection
Options for postcoital contraceptives?
- L-Norgestrel
- Combined oralcontraceptive
Options for Intractable dysmenorrhea or uterine bleeding?
- Conjugated estrogens
- ethinyl estradiol
- oral contraceptive
- depot injection of medroxyprogesterone acetate
- GnRH agonist
Options for infertility?
- Progesterone and other drugs such as clomiphene
- hMG and hCG
- GnRH analogs
- bromocriptine
Options for endometriosis?
- Oral contraceptive
- depot injection of medroxyprogesterone acetate
- GnRH agonist
- danazol
Options for osteoporosis in postmenopausal women?
- Conjugated estrogens
- estradiol (preventive) and raloxifene
Options for hirsuitism?
Combined oral contraceptive
other drugs such as –spironolactone, flutamide, GnRH agonist
What are the sources and physiological functions of progesterone?
Sources of progesterone are: Corpus Luteum, placenta, testes and adrenal cortex
Physiological Functions: Elevation of
progesterone signifies –ovulation
• Stimulates endometrial glandular secretion
• Maintains pregnancy –pro-gestation
• Decrease myometrial contraction and effects
uterine smooth muscle relaxation
• Associated with increase body temperature
• Produce thick cervical mucus that inhibits sperm
access into uterus
• Prevent endometrial hyperplasia and decrease
estrogen receptor expression