Contraceptives (female and male) Flashcards
What percentage of women have access to contraceptives in Canada vs the US?
Canada 90%
USA 50-60%
What are some traditional/natural contraceptives?
rhythm (periodic abstinence), withdrawal and lactational amenorrhea method (LAM)
Is access to contraceptives different depending on age group?
yes, Proportion of women with needs met is age dependent
Access not as good for the 15–19-year-old age group
Types of female contraceptives, reversible?
Fertility awareness (know when fertile) - 24%
Withdrawal - 22%
Female condom - 21%
The pill - 9%
The patch - 9%
Implant - 0.05%
Intrauterine Device (IUD) - 0.2%LNG, 0.8% Copper T
Types of female contraceptives, irreversible?
Abdominal, laparoscopic, and hysteroscopic) - 0.5%
Types of male contraceptives, reversible?
Male condom - 18%
withdrawal - 22%
Spermicide - 28%
The endocrine system?
A hormone is a chemical messenger that circulates in the body and has an effect on distant cells
Types of male contraceptives, irreversible?
Vasectomy - 0.1%
Components of the endocrine system affecting fertility?
Hypothalamus: GnRH released, act on receptors in
Anterior pituitary: LH, FSH, 2 hormones produced, go through circulation, regulate activity
End organ function: Testis, ovary, (gametogenesis, gonadal hormone production)
Hypothalamic-pituitary-ovarian axis?
GnRH, LH, FSH reach to ovaries and affect specific cells and functions, the net result is the production of an oocyte that can be fertilized and the production of hormones; estrogen, progesterone, steroids which can regulate the communication loop, negative feedback on the hypothalamus and the pituitary
Gonadotropin Releasing Hormone (GnRH)?
Pulsatile GnRH stimulates LH and FSH secretion by the anterior pituitary
Shape of the message is also important in the type of reaction produced
Luteinizing Hormone (LH) and Follicle Stimulating Hormone (FSH)?
Pulsatile FSH and LH released by the anterior pituitary stimulate maturation of ovarian follicles and steroid synthesis
They look very similar in terms of their chemical structure, one common subunit and one different one
Released in a pulsatile manner (waves, not a continuous signal, different shapes produced by the signal, no signal pattern)
What does LH do?
Acts on theca cells, layer of cells in the ovary involved in follicle maturation
- Increase steroid synthesis
- Increases FHS receptors
What does FSH do?
- Regulates follicle growth and maturation
- Increases the activity of cholesterol side chain cleavage (CYP11A1- synthesis of progesterone) and aromatase (converts Testosterone to E2/estradiol) in granulosa cells (internal layer)
Nuclear steroid Hormone Receptors?
Estradiol and progesterone interact with hormone receptors, bind hormone LBD ligand binding domain, there are specific DNA binding domains DBD that interact with DNA and along with transcription factors regulates the transcription of hormone responsive genes.
(Basically, regulating the transcription of a bunch of genes involved in processes needed for estrogen or progesterone to act in the body)
What are the progesterone and estrogen receptors
Progesterone receptor:
hPR
estrogen receptor:
2 different types, specific drugs can activate only one type
hER beta
hER alpha
Progesterone action?
Interacts with receptor in nucleus, activates gene expression and get biological function
There are also membrane receptors that activate secondary messengers, to create biological function
Nuclear hormone receptors bound by progesterone, estrogen, testosterone activate specific genes that are involved with the specific hormone receptor
Estrogen receptors?
Genomic response activating the transcription of specific genes that cause biological function
Also, non genomic responses
Estrogens and progestins as drugs for what effect?
- Fertility control
o Contraception
o Ovulation induction - Hormone Replacement Therapy (after menopause)
- Cancer chemotherapy
What hormones regulate the menstrual cycle?
LH and FSH regulate the cycle, peak levels around the follicular rupture
Progesterone peak levels when?
Progesterone synthesis is stimulated by the other hormones, peak progesterone in the luteal phase
How is the endometrial lining built up?
Uterine endometrium is stimulated by the other hormones, the build up of the lining depends on the hormones, if ovulation happens and egg did not fertilize the lining will be lost.
Regulation of Ovulation, positive feedback?
Specific positive and negative feedback
Steep incline in estradiol stimulates LH and FSH production
Increase in E2 (estrogen) greater than the threshold triggers an increase in GnRH and a big increase in LH
What does the midcycle LH surge do?
Stimulates follicle rupture and ovulation
Regulation of Ovulation – negative feedback?
Increase in Estrogen and Progesterone decreases LH and FSH release from Pituitary
Fertility Awareness-Based Methods?
Monitor things like basal body temperature, increase in progesterone, higher body temperature
Can know what your ovarian activity is, progesterone is higher when ovulation occurs
Effectiveness 24% (24 or more pregnancies per 100 women per year)
The pill?
The pill 9% effective
Combination oral contraceptives – analogs of estrogen and progestin
The analogs are less rapidly inactivated than the natural hormones
what are some estrogen analogues?
Ethinyl estradiol
Estradiol valerate
When did the FDA approve the pill for infertility and menstrual irregularities?
1957: FDA approves for: infertility, menstrual irregularities
1960: FDA approval of combination pill
What has changed since the original contraceptive pill?
Since the original pill, the dosages have changed, decreased amount of estradiol
Combination pill types, an estrogen and a progestin?
- Monophasic – 1 month cycle – all pills the same
- Multiphasic- active pills contain different amounts
- Extended cycle – typically 12 weeks of active pills
(also progestin only pills, for people who estrogen is not advised)
How does the oral contraceptive pill block the menstrual cycle?
If you take an oral contraceptive, makes a constant source of estrogen and progestin, so there is a dampening of the feedback, no LH or FSH surge. Since there is no peak GnRH, LH, FSH there is no cycle
The feedback inhibits the LH, FSH, GnRH, and higher brain centers, therefore they impact the signaling from the brain down to tell the ovaries what to do, not going to have a ripe follicle or ovulation
Not the same build up of the lining
What does the pill do? (3)
- Prevent the ovary from releasing an egg
- Thicken the cervical mucus to make it difficult for sperm to reach the egg
- Thin the lining of the uterus to make implantation of fertilized egg more difficult
Oral contraceptive pill, perfect use vs typical use?
- Perfect use failure rate of 0.3%
- Typical use failure rate in the first year 9%
- Failure is related to poor compliance
Basically, you have to take it every day at the same time
Consequences of missing a pill?
Missed 1 not so bad, miss one to 5 the pregnancy rate goes up a bit, but if you miss 6-19 the rate is much higher for pregnancy
Drug interactions with the pill?
Mechanisms:
Induction of P450s using barbiturates, phenytoin, Rifampicin
Entero-hepatic circulation using ampicillin, tetracycline, neomycin (bacteria in GI tract that remove the drugs from circulation, if take antibiotic it will decrease that bacteria)
The reason why the pill works is because it delivers a constant low amount of progesterone and estrogen, if you were able to metabolize it faster, so you are losing the low constant level
Contraceptive pill advantages?
- Periods are more regular
- Can be used for women over the age of 40
- May decrease menstrual cramps and bleeding, anemia
- May be associated with a decreased risk of ovarian and endometrial cancer, colorectal cancer
- May decrease breast tenderness and acne
- Does not interfere with sexual intercourse
- May increase bone density
Contraceptive pill disadvantages?
- Increased risk of venous thromboembolism
- There may be a slight increase in breast cancer, the use of oral contraceptives in BRCA1/2 carriers is controversial but appears to be associated with a decreased risk of ovarian cancer and no increase in breast cancer
- Increased risk for smokers greater than 35
Who should not take the oral contraceptive pill?
Women who smoke should NOT use oral contraceptives, increased risk of mortality
Oral contraceptive patch?
- 150micrograms norelgestromin (NGMN)
- 20 micrograms ethynyl estradiol (EE)
- Gives this dose every day
- Slow release of hormones
- Reversible – new patches are applied weekly
- Don’t have to remember to take the pill each day
- Mechanism of action very similar to the pill
Patch Efficacy and compliance?
- High efficacy
o Overall, Pearl index of 0.88 (number of pregnancies per 100 women per year)
o After 6 cycles, overall pregnancy possibility is half that of OC users - May be less efficacious in women greater than 90 KG, 198 pounds
- Superior compliance with patch that OC
o Patch compliance unaffected by age
o Lower compliance with OC in younger compared with older subjects
What are contraceptive implants?
Little capsule
Contain a progesterone analog such as Levonorgestrel
Implants are 99% effective
Can keep the implant for years
Mean LH Hormone levels during menstrual cycle of Levonorgestrel (Norplant) users and control
Norplant users have a much-decreased LH peak
Type of IUD intrauterine devices?
- Hormonal IUD: releases levonorgestrel (lasts 3-5 years)
- IUDs containing copper wrapped around the base (lasts 10 years)
Emergency contraception, “the morning after pill”?
- PLAN B (levonorgesterol) Is a progesterone analog
- Ella (Uliprostal acetate) is a selective progesterone receptor modulator
The morning after pill how does it work?
- Temporarily block ovulation
- Prevent fertilization
- These drugs can be used to induce a withdrawal bleed up to 5 days after unprotected sex
Medical Termination of Pregnancy (during the first 9 weeks of gestation) what drugs are used?
Mifepristone (RU-486) + Misoprostal
What is mifepristone?
Mifepristone is a progesterone receptor antagonist (block action of progesterone)
What is Misoprostal?
Misoprostal, a prostaglandin analog, dilates the cervix and induces uterine contractions (implanted embryo can be expelled after progesterone’s blocked function)
What do leydig cells do?
Leydig cells:
Outside the seminiferous tubule, produces high local testosterone concentrations
They regulate sperm production
How much testosterone do men produce each day?
Adult men produce 5-7mg of testosterone daily
Testosterone produced in Leydig cells
Spermatogenesis?
Goes from diploid spermatogonium, to haploid sperm
Mitosis, meiosis, meiosis 2, differentiation
Sperm concentrations in most fertile men are > or equal to 15 million/ml (15-200million/ml)
How much does sperm concentration have to decrease to have a low risk of pregnancy?
If sperm concentrations are suppressed to < 1 million/ml, the risk of pregnancy is 1% per year
Human daily sperm production is not as good as a Boar or a ram
How long is spermatogenesis?
Man – 64 days
Takes a long time, over 2 months, to get to make spermatozoa
Feedback Mechanisms Operating in the male?
The Hypothalamus releases GnRH
GnRH interacts with receptors in the pituitary
The pituitary gland releases LH and FSH
LH interacts/activates Leydig cells that can move outside the tubule and make testosterone and estradiol
FSH acts on Sertoli cells in the testis which supports early germ cells
Leydig cells production of testosterone and estradiol cause a negative feedback signal to the hypothalamus to stop producing GnRH and on the pituitary
Sertoli cells produce inhibin-B that inhibit the pituitary
Testosterone Biosynthesis?
Inside Leydig Cells
Extracellular lipoprotein acts on cholesterol
Cholesterol is the starting material
LH binds to receptor, regulates how much testosterone Is made
Testosterone can be metabolized through estrogen
P450c17
Human androgen receptor gene: structural organization and protein
On the X chromosome
There are 3 domains:
- NH2 terminal domain
- DNA binding domain
- Ligand binding domain
Find a specific sequence in DNA that needs to be turned on
Mechanism of Androgen action?
- Testosterone and dihydrotestosterone (DHT) enter the cytoplasm
- The testosterone is converted to DHT by 5 alpha-reductase,
- DHT binds to androgen receptors with the help of coregulators
- Once bound the androgen receptors and DHT move to the nucleus
- The RNA polymerase 2 attaches and transcription starts
What converts testosterone to DHT?
- 5 alpha reductases
What converts testosterone to estradiol?
Aromatase
Where is testosterone found?
Testosterone:
- Muscle
- Bone marrow
- Bone
- Brain
Where is DHT found?
DHT:
- External genitalia
- Prostate
- Skin
- Hair
Where is estradiol found?
Estradiol:
- Bone
- Brain
- Breasts
Androgen metabolites and behavior?
- Estrogens: decrease eating
- DHT: increases eating
Aromatase blockers prevent estrogen formation from testosterone effects?
- Increases copulation
- Increases activity
Testosterone is related to aggression?
CNS: aggressive behavior
Male mice study, aggressive before castration
Post castration there were much less biting attacks, less aggression
When given back 150 micrograms of testosterone a day, the mice became more aggressive again
What percentage of US couples rely on male contraceptive methods?
40%
Impact of condom use on the HIV epidemic?
117 million HIV infections have been averted by the historical scale up of condom use
What is a vasectomy?
Cutting the vas deferens (tube)
Blocks the ability of sperm to be ejaculated
Reversibility: putting it back together – vasovasotomy
Difficult to reconnect, reversibility is an issue
Might not be able to restore function
What is the male contraceptive initiative?
Try to fill the gaps between effective but irreversible vasectomies to less effective male contraception, condoms
Not many funds for male contraception research, so the initiative was created
What effects can giving sustained levels of testosterone have on sperm production?
By giving rabbits sustained levels of testosterone
At first the testosterone was being produced from the Leydig cells and sperm was being produced
After a bit the testosterone mostly came from the implants and no sperm was produced
(The endogenous feedback loop was shut down in the Leydig cells and the testis)
When more testosterone is added there is enough to produce sperm
- When T comes from Leydig cells, germ cells get developed
- When T comes from implant, germ cells don’t get developed
How can giving testosterone and estradiol reduce sperm production? (T-E implants)
Mix the 2 steroids (testosterone and estradiol)
At some point there will be no real sperm made, but if give too much hormone and sperm can be made
No sperm, can use as a contraception in theory
Response to T-E implants in rats over time?
- Beginning: normal
- Then shuts down Leydig production of T
- Then shut down testosterone secretion
- Serum testosterone (circulation levels) is the same
Fewer sperm in the testis, takes about 2 months because the cycle takes that long
What is the main purpose of hormonal male contraception?
Decrease levels of Testosterone that Sertoli and germ cells see, reducing their production
Methods of Hormonal Suppression of sperm Production? (8)
- Testosterone undecanoate (TU) – injections every 1-2 months
- Testosterone enanthate (TE) – weekly injections
- 7-Alpha methyl-19-nortestosterone (MENT) – yearly implant
- TE/progestogen combination – weekly injections + daily pills
- Testosterone-estradiol – yearly implant
- Testosterone and Nestor one- topical gels (NH ongoing?)
- Di Methenolone undecanoate (DMAU) and 11 beta-methyl-19-mortestosterone-17-beta-dodecyclarbonate (MNTDC)- oral doses – early-stage trials
What is Dimethandrolone Undecanoate (DMAU)?
- Androgen and progesterone receptor agonist
- Not aromatized – no estrogenic activity
- Not a substrate for 5 alpha-reductase
- (if block these , no metabolite activity, more specific
How long do male hormonal approaches take to be effective?
2 months
Non-hormonal approaches, thermal contraceptives?
- Hot baths
- Heating devises
- Heating underwear
- Silicone ring
- Ultrasound
Do have some effect but not that much
Drugs that cause Azoospermia
Block spermatogenesis because it blocks meiosis, not selective so acts all over the body, not very good for healthy men
What is Gossypol?
- Developed in China
- Cotton seed oil extract (effects spermatogenesis)
- Daily pill
- Suppresses sperm production
- Reversibility depends on length of exposure (not for sure)
- Irreversible in 10-20% of men (if take it for too long it becomes more irreversible)
- Hypokalemic effect (disturbs potassium levels)
Retinoic acid deprivation?
Vitamin A deficient
No germ cells
Nucleus hormone receptors
Germ cells need retinoic acid\
How is retinoic acid targeted?
WIN 18,446 – inhibits retinoic acid synthesis: induces a disulfiram reaction in men who drink alcohol
YCT529 – RAR alpha antagonist (retinoic acid receptor antagonists, block the synthesis of Retinoic acid)
(blocks a receptor that is important for breaking down alcohol (so won’t be able to drink))
What does inhibition of BRDT cause?
Inhibition of BRDT (a bromodomain protein)
BRDT is required for meiosis
JQ1 also inhibits other bromodomain proteins, leading to toxicity
Inhibition of fertilizing ability of sperm? (4)
- Blockers of epididymal functions
o Steroid 5 alpha-reductase inhibitors (blocks DHT formation) - Nifedipine (calcium channel blockers)
o Prevents enzyme action needed for fertilization (not totally specific) - Mifepristone (RU 486)
o Makes sperm temporarily immotile - Target EPPIN, a small protein coating sperm
o Affects sperm motility (if can’t move will not reach oocyte)
What is Eppin?
Eppin, a human sperm surface protein, is important in sperm motility
(more specific)
Serum Testosterone Concentrations throughput male life span?
- High in fetal males (programing time)
- Goes down then back up in New borns
- Is very low prepuberty
- Increases a lot at puberty
- Stays high as an adult
- Starts to decline as you age
Need specific amounts of testosterone for different events in life, then the amounts go down
Symptoms associated with testosterone Deficiency?
- Sexual dysfunction: decrease libido and erectile dysfunction
- Adverse metabolic effects, ex. coronary artery disease
- Decreased bone density
- Cognitive function?
Potential benefits and risks of hormonal replacement therapy in older men?
Testosterone injection: preserve/improve bone mass
Testosterone patches increase muscle mass and strength, increase physical function
Testosterone solution: increase libido
Testosterone roll-on: improve well being and mood, improve aspects of cognition?
Androgen misuse and abuse
- Rejuvenation fads
- Elite sport enhancement (single androgen, unregulated designer androgens, timing)
- Image enhancement and body building (may involve massive doses)
Only useful in androgen deficiency otherwise have adverse effects
