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Phar300 > lect 15 male contraceptive > Flashcards

lect 15 male contraceptive Flashcards

(60 cards)

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1
Q

sperm is generated from where

A

reproductive stem cells in testis specifically in seminiferous tubules

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2
Q

pathway of sperm

A

testis–>epididymis–>Vas Deferens–>urethra

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3
Q

place where sperm matures how and why

A

epididymis to acquire the ability to fertilize an oocyte. Sperm must differentiate and reduce size of its genetic material and develop a propulsion system

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4
Q

process where diploid stem cells spermatogonia become haploid spermatozoa and days that it takes place

A

spermatogenesis and 64 days

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5
Q

spermatozoa lack what

A

LH and FSH receptors

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6
Q

cells found outside the seminiferous tubule

A

leydig cells

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7
Q

LH acts on what and triggers what

A

Lh receptors of leydig cells and triggers testosterone synthesis

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8
Q

production of local testosterone is important for what maturation

A

germ cell production and maturation of germ cells into spermatozoa

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9
Q

testosterone release causes what feedback

A

feedback inhibition of LH AND GnRH

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10
Q

testosterone is also transported where

A

sertoli cells

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11
Q

concentration of testosterone in seminiferous tubules vs circulation

A

10 times higher

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12
Q

cells found inside seminiferous tubules

A

sertoli cells

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13
Q

mother cells of germ cells in men

A

sertoli cells

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14
Q

what acts on sertoli cells

A

FSH in the fsh receptors

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15
Q

synthesis of testosterone

A

cholesterol side chain cleaved by enzyme. cholesterol than modifies into pregnenolone until into testosterone

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16
Q

testosterone can be further metabolized into whaat

A

dihydrotestosterone DHT and estradiol

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17
Q

enzyme to make DHT and modification

A

5a reductase. reduction of a double bond

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18
Q

affinity of DHT on androgen receptors

A

higher affinity for androgen receptors than testosterone

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19
Q

estradiol use in men

A

production of estrogen in testis

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20
Q

human androgen receptor on which chromosome

A

X chromosome

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21
Q

what happens to androgen receptor upon ligand binding

A

receptor dimerizes upon ligand binding and interacts with androgen response elements in genome to turn on synthesis of genes that are androgen dependent

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22
Q

the presence of 5a reductase and aromatase in local tissues allows for what

A

differential expression in tissues

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23
Q

steroid pyramid

A

cholesterol>progestins>androgens>estrogens

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24
Q

testosterone target what organs mainly

A

mainly muscle, bone marrow, bone, brain

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25
DHT target organs (4)
external genitilia, prostate, skin and hair
26
stimulation of hair growth requires block of what enzyme
5a reductase
27
estradiol target organs (3)
bone, brain, breast
28
most direct way we can block sperm release
block vas deferens
29
methods of male contraceptive (4)
condoms, vasectomy, withdrawal, hormonal
30
hormonal contraceptive men
block cycle to prevent local testosterone for sperm production
31
concentration of testosterone for spermatogenesis compared to concentration required to maintain male features
10 times higher for spermatogenesis
32
testosterone administration contraceptive method and what is the goal
administrating exogenous testosterone for negative feedback, inhibiting local testosterone synthesis administrating right amount of testosterone to enable feedback inhibition without inducing spermatogenesis goal: block hypothalamic-pituitary axis to control testosterone levels
33
what do we get from sustained dose of testosterone in rabbits expriment and what happens if we increase that dose
we blocked the feedback and turned of leydig cells. middle of graph we see axis has been turned off and no germ cells at that specific concentration of exogenous circulating testosterone. plasma testosterone measure is the one from the implant. as we keep increasing implant dose, we eventually get enough testosterone to maintain spermatogenesis
34
problems with testosterone administration method
in species like rats and mokeys, there is less predictability in when do we get no sperm production. too much heterogeneity. difficult to calibrate the dose to get the right one
35
what are PDS implants
combination of testosterone and estradiol that can completely shut off spermatogenesis by feedback inhibition. estradiol is more potent in inhibiting sperm production by feedback inhibition.
36
results of PDS implants
serum LH undetectable, spermatids much lowered. hormones levels not changed so no change in secondary sex characteristics
37
problems with PDS method
hard to calibrate. takes 3 months to wipe out spermatogenesis in humans. in rats it takes 57 days
38
testosterone and progestin hormonal method: androgen analog that is an androgen and progesterone receptor agonist
dimethandrolone undecanoate
39
characteristics of dimethandrolone undecanoate benefits
not aromatized so no estrogenic activity not a substrate for 5a-reductase. reduce side effects seen in previous therapies like that of estrogen suppresses LH and FSh
40
testosterone analog that suppresses serum gonadotropins so cant act on leydig cells and sertoli
11beta-MNTDC
41
name for no sperm production by drugs
azoospermia like cancer drugs
42
control of meiosis method by control of retinoic acid effect on sperm
if we make retinoic acid is absent either from diet or chemically at certain stages of sperm development, we can block spermatogenesis, no germ cell production but be specific to testis because other tissues need retinoic acid. retinoic acid important for sperm maturation
43
drug inhibiting what enzyme in testis and liver for retinoic acid synthesis consequence it had on mice
WIN 18,4666 inhibits enzyme ALDH1A in mice only have undifferentiated spermatogonia and no germ cells
44
cotton seed oil extract that suppresses sperm production and it side effects
gossypol. irreversible in some man and hypokalemic effect (high potassium levels)
45
sperm chromatin contraceptive method
dna is six fold more compacted in sperm than somatic cells. altering 3d structure dna of sperm may alter its swim capacity
46
drug targeting bromodomain containing proteins in sperm chromatin contraceptive method and what was the problem
JQ1 bromodomain containing proteins thought to be germ cell specific but is not
47
inhibition of fertilizing ability contraceptive method
inhibiting maturation and fertilization ability of sperm in epididymis since it only takes 7-10 days compared to germ cells taking 2 months to become sperm
48
immunocontraception method and problem
men have blood-testis barrier in testis to protect it so many things cannot get in. Developing antibodies to sperm proteins, epididymal proteins and germ cells but method not reversible
49
serum testosterone concentration throughout lifespan
high in fetal (for male patterning and development of specific processes and tissues) High in neonatal (to modify sex specific features) large increase in puberty/adult. low pre puberty
50
pulsatile concentrations of testosterone during which period
puberty and adulthood
51
drug methods for men when decreasing testosterone levels (4) called androgen therapy
testosterone, DHEA, Melatonin, human growth hormone
52
does androgen replacement therapy make men more fertile
NO, we see reduced sperm count
53
athletes using androgens for what and consequences
increase bone mass and growth but likely become sterile
54
estrogen levels affect what and how can we inhibit it
eating, copulation, and activity | block aromatase
55
DHT levels affect what habit
eating
56
what is linked to the temporary aggressiveness seen in adolescents
pulsatile changes in testosterone concentrations
57
gradual decrease of testosterone over the age of 30 leads to consequences in what
libido, muscles, activity
58
administrating testosterone in old men is only useful in what and administered how
androgen deficiency administered as injection, patch, solution, or roll on
59
androgen replacement therapy benefits (4)
1. improve bone mass 2. increase muscle mass and strength 3. increase libido 4. improve well being and mood
60
androgen replacement therapy negative effects (alot)
1.Headaches 2.Baldness 3.strokes blood clots 4. High blood pressure 7. aggressive behaviour 10. severe acne 11. development of breasts 12. liver damage 13. enlarged prostate 14. shrinkage of testicles nausea bloating reduced sperm count

Phar300 (18 decks)

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