Endocrine 6 (Reproduction) Flashcards
What hormone regulates the menstrual cycle?
GnRH regulates the secretion of FSH and LH
Endogenous Estrogens
- Examples
Estrone, Estradiol, Estriol
Estradiol = Most Potent
Synthetic Estrogens
- Examples
Ethinylestradiol, Mestranol
Estrogen
- Receptor Signalling
Reproductive Action
- Nuclear Estrogen Receptors (ER)
–> ER alpha and ER beta
–> Transcription Factors that regulate gene expression
Vascular Action
- GPCR
–> GPR30 or GPER
1. Activation of endothelial nitric oxide synthase (eNOS)
2. Increases NO
3. Vasodilation
Combined Pill
- Contains?
Ethinylestradiol (Synthetic Estrogen)
- Natural Estrogen are susceptible to hepatic metabolism
2nd Generation Progestogens
- Norethisterone, Levonorgestrel, Ethynodiol
or
3rd Generation Progestogens
- Desogestrel, Gestodene
Combined Pill
- MOA
Estrogen increases Negative Feedback on anterior pituitary
- Suppresses Ovarian Follicular Development
Progestogen increases Negative Feedback on anterior pituitary
- Inhibit LH secretion –> Prevents Ovulation
Both work in combination to make reproductive tract unsuitable for contraception and implantation
Combined Pill
- Acne: Estrogen vs Progesterone
Acne is caused by free androgens
Estrogen: Increases sex hormone binding globulin that remove free androgens
–> Decrease Acne
Progesterone: Increases amount of androgen
–> Increases Acne
Combined Pill
- Adverse Effect
Thromboembolism
- Patients that smoke or have a history of hypertension should avoid 3rd generation Progestogens
Increase Blood Pressure in some Women
- Caused by increase in circulating angiotensinogen
- Stop using combine pill and switch to a progestogen only therapy
Combined Pill
- Beneficial Effect
Reduced risk in ovarian and endometrial cancer
Decreased menstrual symptoms
Reduced iron deficiency anemia
Hormonal Contraceptives
- Breast Cancer
Actually do not increase the risk of breast cancer
- Only appears like it does due to greater monitoring when using contraceptives
- Allows us to catch the cancer early
2nd Generation Progestogen vs
3rd Generation Progestogen
3rd gens are less likely to cause acne
Higher risk for thromboembolism
Progestogen Only Pill
- Contains?
Norethindrone (1st Generation)
or
Ethynodiol (2nd Generation)
Progestogen Only Pill
- MOA
- Makes cervical mucus inhospitable to sperm
- Inhibits implantation (Altering endometrium)
- Alters motility and secretions of fallopian tubes
Alternative for people who experience blood pressure increase from estrogen
Postcortical Contraception
Oral Dose of Levonorgestrel
- Used in emergency, dose is repeated 12 hours later
- Causes nausea and vomit
–> Take with Dimenhydrinate (Gravol)
Long-Acting Progestogen-Only Contraception
Depot Medroxyprogesterone
- Given intramuscularly (Slow release of progestogen)
- Menstrual irregularities are common
- Infertility may persist for months even after stopping treatment