Androgens -12 Flashcards
Testosterone
- testosterone is secreted by the ___
- in men, there is a constant ___ of testosterone produced daily (95% ___ cells, 5% by adrenal glands)
- testosterone plasma levels: men - ___ mcg/dL after puberty. women - ___ mcg/dL
- circulating testoserone is bound to ___ (65%), ___ (33%), ___ (2%)
- testis
- 8 mg, Leydig
- 0.6 mcg/dL, 0.3 mcg/dL
- sex-hormone binding globulin (SHBG)
- albumin
- free
Regulation of testosterone synthesis
- the hypothalamus releases ___
- anterior pituitary releases ___ and ___
- LH triggers ___ cells in the testis to produce ___. FSH triggers ___ cells to produce ___.
- Testosterone is responsible for the development of sex organs and also inhibits the ___ and ___ through negative feed back.
- GnRH (Gonadotropin-releasing hormone)
- LH (luteinizing hormone) and FSH (follicle stimulating hormone), sperm
- hypothalamus and anterior pituitary
Testosterone metabolism
- in target tissues, testosterone is broken down into ___ by 5α-reductase
- testosterone can also be broken down into ___ by aromatase
- 5α-Dihydrotestosterone
- 17β-Estradiol
T or F: 5α-Dihydrotestosterone is a more potent major active androgen
True
better binding/more activity than testosterone
Testosterone excretion
- occurs in the ___
- inactivated to ___ and ___
- then conjugated and excreted to the ___
- liver
- androsterone and etiocholanolone
- urine
Adrenal androgens
3 intermediates of testosterone
* ___, ___, and ___
* have ___ androgen effects
* large amounts produced in the ___
- androstenedione, dihydroepiandrosterone (DHEA), dihydroepiandrosterone sulfate (DHEAS)
- weak
- adrenal glands
Physiologic effects
- penile and scrotal growth
- ___ and ___ skin
- pubic, axillary, and beard hair
- deepening of voice
- skeletal growth followed by ___ closure
- increase in lean body mass → positive ___ balance
- stimulation and maintenance of sexual function
- stimulation of ___ production
- decrease in ___ levels
- oily and thick
- epiphyseal
- nitrogen
- erythrocyte
- HDL
clinical uses
Androgen replacement therapy in men
* Male ____ (testosterone deficiency)
* Hypopituitarism - promote production of ___ to produce sperm
- hypogonadism
- FSH
clinical use
Gynecologic disorders
* endometriosis (___)
* replacement therapy for ___ women (in combo with estrogens) (controversial)
* eliminates ___ bleeding
* enhances ___
- danazol
- postmenopausal
- endometrial
- libido
must be used with great caution due to adverse effects
clinical use
Protein anabolic agents
* reverse ___ loss after trauma/surgery/prolonged immobilization. Promotes ___ growth.
- can also be used for ___pause
- protein
- andropause
Synthetic androgens
- when administered ___, testosterone is readily absorbed but largely ___.
- ___ forms are more active orally. Example: ___
- ___ forms have prolonged absorption time and greater activity for intramuscular administration. Examples: ___, ___, and ___
- orally, inactivated
- 17-alkyl, methyltestosterone
- ester, propionate, enanthate, cypionate
Anabolic steroids in sports
- doses ___ times larger than the daily normal production
- harmful changes in ___ levels
- acne
- high ___
- hepatic dysfunction in case of ___ steroids
- large doses of anabolic steroids suppress the secretion of ___ → testicular ___
- 10-200
- cholesterol
- high blood pressure
- 17-alkyl
- gonadotropins, atrophy
Adverse effects in women
- hirsutism
- acne
- amenorrhea
- clitoral enlargement
- deepening of voice
Adverse effects in men
- acne
- sleep apnea
- gynecomastia
- azoospermia and testicular atrophy
- increased aggresiveness adn psychotic symptoms
Antiandrogens
___ inhibitors
* block the conversion from testosterone to 5α-dihydrotestosterone.
5α-reductase