E2 L2: Androgens

Question 1

Describe the regulation of testosterone synthesis

Answer 1

Negative feedback = too much - less production; too little - more production

Question 2

Distinguish the role of LH in testosterone synthesis and spermatogenesis

Answer 2

Stimulates Leydig cell T producton

Question 3

Distinguish the role of FSH in testosterone synthesis and spermatogenesis

Answer 3

Stimulates in Sertoli Cells (in synergy with testosterone, the production of regulatory molecules and nutrients needed for the maintenance of spermatogenesis. Hence, both T and FSH regulate spermatogenesis indirectly through sertoli cells

Question 4

T/F: Production of LH, Testosterone, and FSH are dependent on each other

Answer 4

True

Question 5

Describe the role of 5a-reductase in spermatogenesis

Answer 5

Testosterone - similar to a prodrug
Converted to more active form by 5a-reductase
More potent
Major active androgen

Question 6

Testosterone is converted by ____ in some tissues to ___

Answer 6

Aromatase; 17B - Estradiol

Question 7

List the physiological effects of testosterone

Answer 7

-Responsible for changes at puberty
-Growth-promoting properties: penile and scrotal growth
Change in the skin (thicker and oiler)
Pubic, axillary, and beard hair
Deepening of the voice
Skeletal growth followed by epiphyseal closure
Increase in lean body mass = positive nitrogen balance (increase muscle, + nitrogen balance = more in body)
Stimulation and maintenance of sexual function
Stimulation of erythrocyte production
Decrease in HDL level
= men have more cholesterol issues than women (heart attack, stroke)

Question 8

Identify the structures of synthetic androgens (names and route)

Answer 8

Methyltestosterone (oral)
Testosterone enanthate (IM)
Testosterone cypionate (IM)

Question 9

T/F: When administered orally, testosterone is readily absorbed by inactivated largely

Answer 9

True

Question 10

Methyltestosterone

Answer 10

Addition of methyl group
-Oral
Much longer half-life due to presence of methyl - cannot be broken down orally

Question 11

Testosterone enanthate and Testosterone cypionate

Answer 11

IM
Has prolonged absorption time and greater activity for intramuscular admin
Prodrugs

Question 12

Assess the effects of structural modification in synthetic androgens (anabolic steroids)

Answer 12

Used in doses 10-200 times larger than the daily normal production to increase strength and aggressiveness
Such effects have been proven only in women (men already have = little to no change)
SIG health risks from long-term use:
Harmful changes in cholesterol levels (High LDL, low HDL)
Acne
High BP
Hepatic dysfunction in case of 17-alkyl steroids large doses of anabolic steroids suppress secretion of gonadotropins = testicular atrophy

Question 13

List the adverse effects of androgens:

Answer 13

SHOULD NOT BE USED IN INFANTS OR PREGNANT WOMEN
-sig disturbances in sex development may occur
Acne
Sleep apnea
Gynecomastia
Azoospermia and testicular atrophy
Increased aggressiveness and psychotic symptoms

Question 14

Adverse effects of androgens: women

Answer 14

Hirsutism
Acne,
amenorrhea
clitoral enlargement
deepening of the voice

Question 15

Adverse effects of androgens: men

Answer 15

Acne
Sleep apnea
Gynecomastia
Azoospermia and testicular atrophy
Increased aggressiveness and psychotic symptoms

Question 16

Describe the pharmacological uses of antiandrogens

Answer 16

5-a reductase inhibitors:
Block the conversion of testosterone to 5a-dihydrotestosterone
Androgen receptor antagonists:
Block the binding of endogenous androgens to the receptor or inhibit the activation of the receptors
-steroidal inhibitors vs. nonsteroidal inhibitors
BLOCK THE ENZYME - reduce this hormone
Blocks the activity of androgen

Question 17

Distinguish the types of antiandrogens: types

Answer 17

5a-reductase inhibitors
Steroidal androgen receptor antagonists
Non-steroidal androgen receptor inhibitors

Question 18

Types of antiandrogens: 5a-reductase inhibitors:

Answer 18

Finasteride:
Benign prostatic hyperplasia (Proscar)
Male pattern baldness
Hirsutism in women
dutasteride:
Benign prostatic hyperplasia
Male pattern baldness

Question 19

Types of antiandrogens: Steroidal androgen receptor antagonists

Answer 19

Cyproterone acetate:
Hirsutism in women
Excessive sex drive in men
Spironolactone:
Hirsutism in women
Acne

Question 20

Types of antiandrogens: Non-steroidal androgen receptor inhibitors

Answer 20

Flutamide:
non steroidal antiandrogen
Prostate cancer
Enzalutamide:
Non-steroidal antiandrogen
Metastatic castration-resistant prostate cancer