Male and Female Hormones Flashcards
What is the role of male and female hormones?
To control reproductive function and secondary sex characteristics in respective gender groups
What are sex hormones classified as?
steroids
Where are sex hormones produced?
primarily by the gonads, with a small amount in the adrenal cortex (insignificant amount to produce physiological effects)
What are the male and female sex hormones?
Male=androgens
Female=estrogens (estradiol) and progestins (progesterone)
What is the control loop for testosterone?
- Gonadotropin releasing hormone (GnRH) is released from the hypothalamus, which causes
- Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) are released from the anterior pituitary, which causes
- Testosterone to be released from the testes
What is the feedback loop for testosterone?
Increased testosterone in circulation inhibits production of these hormones (LH, FSH, GnRH) from the hypothalamus
What are the levels for testosterone in circulation?
Fairly constant until aging, where there is decreased production
What are the results (pros/cons) of testosterone replacement therapy?
Benefits on body composition, strength, bone mineralization, glucose metabolism, mood, and libido
May be an increased risk of prostate cancer
What are the reasons to administer androgens?
- Protein loss, muscle catabolism, effects of HIV (rarely first choice of physicians, mixed success)
- Delayed puberty-androgens may be used on a short term basis to kick start puberty, as long as no underlying pathology exists
- Limited use in hormone sensitive tumors
- Anemia-since testosterone is a potent stimulator of EPO, but more direct drugs are preferable
- Hereditary angioedema (defect in clotting factors)-may use androgens prophylactically due to action on liver to restore clotting factors
What are the adverse effects of androgens in women?
Hirsutism, deepening voice, enlarged external genitalia
What are the adverse effects of androgens in men?
Bladder irritation, breast swelling and soreness, frequent or prolonged erections, increased risk of prostate cancer
What are the adverse effects of androgens in children?
Accelerated sexual maturation and premature closure of the epiphyseal plates
What are the adverse effects of long term use of androgens?
Liver damage/carcinoma, HTN, fluid retention
What is the function of antiandrogens?
inhibit the synthesis or the effects of androgen production
When might antiandrogens be used?
In the tx of prostate cancer or benign prostatic hypertrophy
What are the antiandrogens?
Finasteride (Propecia, Proscar), dutasteride (Avodart)
Why might someone abuse androgen?
anabolic steroids are used to enhance athletic performance and increase muscle size and strength
How might someone take androgens to increase their effects?
Taking them in a stacking dosage
Review table 30-2 for common drugs
Review
How might an athlete take steroids to avoid detection?
By using a certain steroid dosing cycle
What are the potential benefits of androgen abuse?
Athletic performance, lean body mass, and muscle strength are improved-undetermined by how much
What other things might athletes use to enhance performance?
Blood doping and growth hormones
What are the adverse effects of androgen abuse?
- *can be severe/fatal**
1. mood “roid rage”
2. liver damage
3. hepatic tumors
4. cardiomyopathy
5. arrhythmia
6. decreased HDL lipids
7. changes in reproductive function
What are the functions of estrogen?
Initiated in puberty:
- Maturation of sexual organs
- Subcutaneous fat stores
- Closure of epiphyseal plates
- Widening of pelvic girdle
What is the function of progesterone?
Less important in sexual maturation-more involved with facilitating and maintaining pregnancy
When is FSH released and what does it do?
Released in follicular phase
Matures into ovum
When is LH released and what does it do?
Released at menstrual midpoint with a smaller burst of FSH for ovulation
Causes the follicle to release the ovum, and become infiltrated with lipids, forming the corpus luteum
What does the corpus luteum do during the second half of the menstrual cycle?
Continues to grow for around 1 week post-ovulation, secretes estrogen and progesterone, which thickens the uterine lining and progesterone stimulates mucus for potential implantation of a fertilized egg
What happens if an egg is not fertilized?
The corpus luteum regresses and menstruation occurs
What happens if an egg is not fertilized?
human chorionic gonadotropin (HCG) is released, takes over the role of LH and prevents the destruction of the corpus luteum
How are estrogen and progesterone produced if an egg is fertilized?
- Corpus luteum persists until 9th-14th week of gestation, producing progesterone to facilitate uterine environment
- Placenta produces estrogen and progesterone thereafter-also facilitates development of mammary glands for lactation
When may estrogen play a role during pregnancy?
In parturitionp
What are the pharmacological uses for estrogen and progesterone?
- contraceptives-altering control between pituitary and ovarian hormones
- osteoporosis-estrogen replacement
- hypogonadism-low ovarian function, bleeding abnormalities
- Failure of ovarian development
- Menstrual irregularities-amenorrhea, dysmenorrhea
- Endometriosis-progesterone and estrogen/progesterone combos
- Carcinoma-metastatic breast cancer treated by estrogen
What are the pros/cons of estrogen replacement therapy?
Definitely improves bone mineralization, may improve plasma lipids, possibly some CV benefit
May have increased risk of stroke and thromboembolic disease
When may be the best timing for estrogen replacement therapy?
starting HRT when a woman is less than 60 years old and within 10 years of reaching menopause
What is the role of HRT and cognitive disorders?
No benefit in protecting cognitive decline in of Alzheimer’s, mixed results in other cognitive studies
Review for clinical used of estrogen/progesterone
30-4/30-5
What are other adverse effects of taking estrogen and progesterone?
abnormal blood clotting, PE, thromboembolism, stroke
How do Selective Estrogen Receptor Modulators work?
Bind to and activate estrogen receptors on certain tissues while blocking the effects on other tissues
Example: can reduce carcinogenic effects of estrogen on breast and uterine tissue while producing favorable effects on bone mineralization and cardiovascular function
What are some examples of SERMs? What are some potential adverse effects?
Tamoxifen (Tamofen, Nolvadex), may increase fertility
Raloxifene (Evista)-primarily used to treat osteoporosis, may also give protection against breast cancer; side effects=hot flashes, bone/joint pain, GI effects, flu-like sx
What are some anti-estrogens?
Clomiphene=treats infertility by promoting ovulation
Fulvestrant (Faslodex)-an antiestrogen used to treat estrogen sensitive breast cancers
What are the functions of anti-progestins?
Used for termination of pregnancy (RU486) Treatment of uterine fibroids and endometriosis Cushing syndrome (block cellular glucocorticoid receptors)
What are hormonal contraceptives? How do they work?
almost 100% effective when taken correctly
varying levels of estrogen/progesterone combos
LH and FSH are inhibited, so there is no ovulation
What are some adverse effects of hormonal contraceptives?
Adverse effects have decreased with newer drugs-less estrogen, better forms of progestins
Still may have risk of thromboembolism, CV events-usually unassociated with risk factors of smoking, HTN, hyperlipidemia
What are some potential beneficial effects of hormonal contraceptives?
May actually protect against endometrial and ovarian cancers; relationship to breast cancer is more complicated
